COMPUTER PROGRAMME

History Of Programming Language

2009-03-05T03:57:00.000-08:00

What is a Programming Language?
• Programming language is a set of words, symbols, and codes that enables a programmer to communicate a solution algorithm to a computer.
• It is needed to allow human begins and computers to talk to each other.
• A programmer can use a variety of programming languages to code a program.
• A program development tool consists of user-friendly software products designed to assist both programmers and non-technical users with the creation of information system solutions.
Traits often considered important for constituting a programming language:
• Function: A programming language is a language used to write computer programs, which involve a computer performing some kind of computation or algorithm and possibly control external devices such as printers, robots, and so on.
• Target: Programming languages differ from natural languages in that natural languages are only used for interaction between people, while programming languages also allow humans to communicate instructions to machines. Some programming languages are used by one device to control another. For example PostScript programs are frequently created by another program to control a computer printer or display.
• Constructs: Programming languages may contain constructs for defining and manipulating data structures or controlling the flow of execution.
• Expressive power: The theory of computation classifies languages by the computations they are capable of expressing. All Turing complete languages can implement the same set of algorithms. ANSI/ISO SQL and Charity are examples of languages that are not Turing complete yet often called programming languages.
Some authors restrict the term "programming language" to those languages that can express all possible algorithms; sometimes the term "computer language" is used for more limited artificial languages.
Non-computational languages, such as markup languages like HTML or formal grammars like BNF, are usually not considered programming languages. A programming language (which may or may not be Turing complete) may be embedded in these non-computational (host) languages.

Generation of Programming Language

• The first generation of language was the machine language. The machine language instruction uses a series of binary digits or a combination of numbers and letters that represents binary digits. Instructions and addresses were numerical.
• The second generation of language was the symbolic instructions or mnemonics and addresses. To convert the assembly language source program into machine language, you use an assembler. Example, IBM, BAL and VAX macro.
• The third generation language was the programmer concentration of structured programming and database management. It is a procedural language that requires the program instruction to tell the computer what to accomplish and how to do it. Example, FORTRAN, ADA, COBOL, Pascal, C and BASIC.
• The fourth generation (4GL) was the non-procedural type language. The programmer only specifies what the program should accomplish without explaining how. Example. SQL, Postscript, and relational database orientation.
• The fifth generation (5GL) was concerned on Artificial Intelligence and Fuzzy Logic.

Advantages and disadvantages of each generation of language

• Readability of the language
 If parts of the program are going to be read or altered separately form the entire program is might be worth considering how legible they are going to be. Clumsy abbreviations should be avoided. Statements such as WHILE LOOP have increased the readability of programs and lead to neater programs.

• Ease of writing the language
 A programming language that is easy to write in can make the process easier and faster. It may help to reduce mistakes, save time and money, and make the program smaller.

• Reliability of the language
 A program that is not robust can cause errors, and code can “decay”. Any language that helps the programmer to avoid mistakes will make it easier to use.

• Cost of development
 Is the language expensive to use and to maintain? Program may need to be updated or re-developed and an expensive language may make this prohibitive.

• Syntax complexity
 Syntax is an important consideration. Clarity and ease of understanding are important, as is a syntax that seems logical and sensible. Errors are very likely to occur where one area of syntax too closely resembles another, and the program may prove difficult to debug.

• Language standards
 Languages that have standards for writing programs have greater readability.

Language Models

• Imperative Languages – are formed from collections of basic commands, most often assignments and I/O, where the execution is sequenced by control structures.

• Functional Languages – are based on lambda-calculus from the 1930’s. Programs consist of collections of function definitions and function applications.

• Logic Programming – consists of collections of statements within a particular logic. Most typically that logic is predicate logic. ProLog.

• Object-oriented languages – Programs consist of objects that interact with each other. Some also associate inheritance and polymorphism with OO language. Smalltalk, Java.

• Declarative languages – are collections of declarations. Many functional and logic languages are also declarative. Declarative languages describe relationships between variables in terms of functions or inference rules and the language executor applies some fixed algorithm to these relations to produce a result.

• Scripting language – work in conjunction with a larger application, support control of a variety of applications, are interpreted, or some combination thereof.

• Parallel language – are collections of processes that communicate with each other.

Evolution of Digital Computers

2009-03-01T03:26:00.000-08:00

Objectives
• Getting students to understand the objectives of the subject, and also including marks distribution for the subject.
• Review historical development of computer systems
• Identify design levels for computer system development
• Discuss descriptive and design tools for each design level
• Compare and contrast various performance metrics for computer systems

Computer Architecture
• Baer: “The design of the integrated system which provides a useful tool to the programmer”
• Hayes: “The study of the structure, behaviour and design of computers”
• Abd-Alla: “The design of the system specification at a general or subsystem level”
• Foster: “The art of designing a machine that will be a pleasure to work with”
• Hennessy and Patterson: “The interface between the hardware and the lowest level software”

• Computer architecture refers to those attributes of the system that are visible to a programmer -- those attributes that have a direct impact on the execution of a program
– Instruction sets
– Data representations
– Addressing
– I/O
• Synonymous with “architecture” in many uses and textbooks
• We will use it to mean the underlying implementation of the architecture
• Transparent to the programmer
• An architecture can have a number of organisational implementations
– Control signals
– Technologies
• Device implementations

Structure and Functions
• Structure is the way in which components relate to each other
• Function is the operation of individual components as part of the structure

Computer Functions
• Historically, a computer was a job title, not a piece of equipment!
• Requirements of a computer:
– Process data
– Store data
– Move data between the computer and the outside world
• Control the operation of the above

Functional View

Evolution of Digital Computers

Operations (1) Data movement

Operations (2) Storage

Operation (3) Processing from/to storage

Operation (4) Processing from storage to I/O

Structure - Top Level

Structure - The CPU

Structure - The Control Unit

Operating System

2008-12-18T23:07:00.000-08:00

A. Learning Objectives

1. Defining Operating System.
2. Identify the various types of OS and discuss the features of the each type

B. Learning Outcomes

1. Identify the various types of OS and discuss the features of the each type
2. To identify the key features of the each types of OS

Objectives
 To provide a grand tour of the major operating systems components
 To provide coverage of basic computer system organization

What is an Operating System?
 A program that acts as an intermediary between a user of a computer and the computer hardware.
 Operating system goals:
 Execute user programs and make solving user problems easier.
 Make the computer system convenient to use.
 Use the computer hardware in an efficient manner.

Computer System Structure
 Computer system can be divided into four components
 Hardware – provides basic computing resources
 CPU, memory, I/O devices
 Operating system
 Controls and coordinates use of hardware among various applications and users
 Application programs – define the ways in which the system resources are used to solve the computing problems of the users
 Word processors, compilers, web browsers, database systems, video games
 Users
 People, machines, other computers

Four Components of a Computer System

Operating System Definition

 OS is a resource allocator
 Manages all resources
 Decides between conflicting requests for efficient and fair resource use
 OS is a control program
 Controls execution of programs to prevent errors and improper use of the computer
 No universally accepted definition
 “Everything a vendor ships when you order an operating system” is good approximation
 But varies wildly
 “The one program running at all times on the computer” is the kernel. Everything else is either a system program (ships with the operating system) or an application program

Computer Startup
 bootstrap program is loaded at power-up or reboot
 Typically stored in ROM or EPROM, generally known as firmware
 Initializates all aspects of system
 Loads operating system kernel and starts execution

Computer System Organization
 Computer-system operation
 One or more CPUs, device controllers connect through common bus providing access to shared memory
 Concurrent execution of CPUs and devices competing for memory cycles

Computer-System Operation
 I/O devices and the CPU can execute concurrently.
 Each device controller is in charge of a particular device type.
 Each device controller has a local buffer.
 CPU moves data from/to main memory to/from local buffers
 I/O is from the device to local buffer of controller.
 Device controller informs CPU that it has finished its operation by causing an interrupt.

Common Functions of Interrupts
 Interrupt transfers control to the interrupt service routine generally, through the interrupt vector, which contains the addresses of all the service routines.
 Interrupt architecture must save the address of the interrupted instruction.
 Incoming interrupts are disabled while another interrupt is being processed to prevent a lost interrupt.
 A trap is a software-generated interrupt caused either by an error or a user request.
 An operating system is interrupt driven.

Interrupt Handling
 The operating system preserves the state of the CPU by storing registers and the program counter.
 Determines which type of interrupt has occurred:
 polling
 vectored interrupt system
 Separate segments of code determine what action should be taken for each type of interrupt

Interrupt Timeline

I/O Structure
 After I/O starts, control returns to user program only upon I/O completion.
 Wait instruction idles the CPU until the next interrupt
 Wait loop (contention for memory access).
 At most one I/O request is outstanding at a time, no simultaneous I/O processing.
 After I/O starts, control returns to user program without waiting for I/O completion.
 System call – request to the operating system to allow user to wait for I/O completion.
 Device-status table contains entry for each I/O device indicating its type, address, and state.
 Operating system indexes into I/O device table to determine device status and to modify table entry to include interrupt.

Two I/O Methods (a) Synchronous (b) Asynchronous

Device-Status Table

Direct Memory Access Structure
 Used for high-speed I/O devices able to transmit information at close to memory speeds.
 Device controller transfers blocks of data from buffer storage directly to main memory without CPU intervention.
 Only one interrupt is generated per block, rather than the one interrupt per byte.

Storage Structure
 Main memory – only large storage media that the CPU can access directly.
 Secondary storage – extension of main memory that provides large nonvolatile storage capacity.
 Magnetic disks – rigid metal or glass platters covered with magnetic recording material
 Disk surface is logically divided into tracks, which are subdivided into sectors.
 The disk controller determines the logical interaction between the device and the computer.

Storage Hierarchy
 Storage systems organized in hierarchy.
 Speed
 Cost
 Volatility
 Caching – copying information into faster storage system; main memory can be viewed as a last cache for secondary storage.

Storage-Device Hierarchy

Caching
 Important principle, performed at many levels in a computer (in hardware, operating system, software)
 Information in use copied from slower to faster storage temporarily
 Faster storage (cache) checked first to determine if information is there
 If it is, information used directly from the cache (fast)
 If not, data copied to cache and used there
 Cache smaller than storage being cached
 Cache management important design problem
 Cache size and replacement policy

Performance of Various Levels of Storage
 Movement between levels of storage hierarchy can be explicit or implicit

Operating System Structure

 Multiprogramming needed for efficiency
 Single user cannot keep CPU and I/O devices busy at all times
 Multiprogramming organizes jobs (code and data) so CPU always has one to execute
 A subset of total jobs in system is kept in memory
 One job selected and run via job scheduling
 When it has to wait (for I/O for example), OS switches to another job
 Timesharing (multitasking) is logical extension in which CPU switches jobs so frequently that users can interact with each job while it is running, creating interactive computing
 Response time should be < 1 second
 Each user has at least one program executing in memory process
 If several jobs ready to run at the same time  CPU scheduling
 If processes don’t fit in memory, swapping moves them in and out to run
 Virtual memory allows execution of processes not completely in memory

Generation of Programming Language

2008-12-14T22:33:00.000-08:00

Advantages and disadvantages of each generation of language

• Readability of the language
 If parts of the program are going to be read or altered separately form the entire program is might be worth considering how legible they are going to be. Clumsy abbreviations should be avoided. Statements such as WHILE LOOP have increased the readability of programs and lead to neater programs.

• Ease of writing the language
 A programming language that is easy to write in can make the process easier and faster. It may help to reduce mistakes, save time and money, and make the program smaller.

• Reliability of the language
 A program that is not robust can cause errors, and code can “decay”. Any language that helps the programmer to avoid mistakes will make it easier to use.

• Cost of development
 Is the language expensive to use and to maintain? Program may need to be updated or re-developed and an expensive language may make this prohibitive.

• Syntax complexity
 Syntax is an important consideration. Clarity and ease of understanding are important, as is a syntax that seems logical and sensible. Errors are very likely to occur where one area of syntax too closely resembles another, and the program may prove difficult to debug.

• Language standards
 Languages that have standards for writing programs have greater readability.

Language Models

• Imperative Languages – are formed from collections of basic commands, most often assignments and I/O, where the execution is sequenced by control structures.

• Functional Languages – are based on lambda-calculus from the 1930’s. Programs consist of collections of function definitions and function applications.

• Logic Programming – consists of collections of statements within a particular logic. Most typically that logic is predicate logic. ProLog.

• Object-oriented languages – Programs consist of objects that interact with each other. Some also associate inheritance and polymorphism with OO language. Smalltalk, Java.

• Declarative languages – are collections of declarations. Many functional and logic languages are also declarative. Declarative languages describe relationships between variables in terms of functions or inference rules and the language executor applies some fixed algorithm to these relations to produce a result.

• Scripting language – work in conjunction with a larger application, support control of a variety of applications, are interpreted, or some combination thereof.

• Parallel language – are collections of processes that communicate with each other.

Introduction to Computing Projects

2008-12-11T22:49:00.000-08:00

Introduction
The Integrated System Project (ISP) undertaken by students in the final year of their Diploma in Computer Studies is the major assignment required to be submitted for the project course that is relevant to their particular program of study. These 05-credit courses extend across the two semesters in the final year of the diploma.

The ISP
An ISP is a sustained piece of work carried out by student which when completed, will reflect the student’s ability to tackle a selected problem in depth and to present their findings in a technical report.

Choose an ISP Title
In the majority of cases, students will decide upon a specific project or project area, and discuss the feasibility of a particular project idea with a member of the academic staff. Students may request to have the opportunity to work on projects related to an area pursued by a member of academic staff, in which case, students will be interviewed for their suitability.

Finding a supervisor
In the first instance you should discuss any ideas for a project with a member of the academic staff. You should do your best to secure the agreement of a member of academic staff to supervise your project. A supervisor will be allocated to you if you are not successful in finding a member of the academic staff to agree to supervise your proposed project.
Meeting supervisor
Regular meetings are essential. Short meetings held every week for the first few weeks will help you to fully establish the details of your proposed project. The frequency of meetings may then reduce to fortnightly or every few weeks depending upon circumstances. On a weekly basis, the amount of time that could be spent with each student is very limited. You should endeavour to plan your project activities to include checkpoints at which times you would have something useful prepared for a meeting with your supervisor. Nevertheless, regular contact throughout the year is essential if your supervisor is to gain a good idea of the work that you put into the development of the project - a factor which will influence the mark that you are eventually awarded for your development work! In the case of part-time students, it may be hard to arrange meetings with the supervisor; less frequent meetings in person may be adequate if frequent contact is made by other means, e.g. telephone, mail, or electronic mail. This may also apply to full-time students if the supervisor is agreeable.

Assessing ISP
Assessment is based on your development work over the period of the project and the final work. The final work may consist of a product and project report. Your supervisor is responsible for assigning a development mark that reflects the work that you have put into the project during the year, and also the way in which you have approached the topic and dealt with the concepts and any problems that may have arisen. For this reason and other reasons that should be self-evident, you should keep your supervisor informed of your progress at regular intervals.

The ISP Report
The project report is a report that you write to record and present the work that you have done and the conclusions that you have reached. It is read and assessed for its clarity and comprehension by both your supervisor and another member of the academic staff who will each award a mark for the project report. The report must be word-processed. Two copies of the report are needed. Planning the shape of the report (e.g. deciding upon chapter headings and their ordering) should commence before the end of the first semester. You will be advised in detail during the project lectures concerning appropriate logical structuring and physical layout of the report. One copy of the completed, unbound project report must be submitted on or before the deadline.

Purpose of the ISP Report
The project report provides a record of the work done in the project, which may serve as a starting point for other projects in subsequent years. The assessment of a project is based mainly on the project report. Without a report it is most unlikely that a project will achieve a pass mark (except perhaps when the absence of a report is for reasons beyond the control of the student). The project report should therefore describe the work done in the project in as favorable a way as possible, and, if the situation arises, explain why some of the intended work was not done. It is further worth bearing in mind that the project report represents probably the largest, individual piece of work carried out by a student during their diploma. Prospective employers are often keen for students recently graduated, to take their projects with them to interviews as a demonstration of ability to work independently and ability to manage their work over a period of time - qualities which are generally accepted to be very desirable in an applicant. It also provides clear evidence of their ability in written communication. Whilst good writing cannot make up for the lack of content, it is always advisable to present the contents in the best possible light by the use of good English and a correctly structured layout.

Logical Structure of the Report
The structuring and content of project reports is covered in full in the project lectures. For information only, the following may serve as a guide:
The following is the standard structure for the project report:
Title Page
Abstract
Preface … … … … … … … … .optional
Acknowledgements
Table of Contents
List of Tables… … … … … … optional
List of Figures… … … … … ...optional
Body of Report
List of References
Appendices
Glossary… … … … … … … … optional

Title Pages
The Title Page contains the project title, your name, the date (month and year) of submission (i.e. May 2008), and the title of the diploma program. There is a required ‘house style’ format for the Title Page. This is given out during the project lectures.

Abstract
The abstract, occupying less than half a page, is a short description of the intention of the project.

Preface
The Preface includes any relevant observations that do not belong in the project itself.

Acknowledgements
It is customary to acknowledge any substantial help, with either the project work or the report, from people and other informal sources.

Table of Contents
The report should be divided into chapters each of which may be divided into sections which may again be divided into subsections and so on. Each chapter and numbered section or subsection should have a title, and the contents page should list the most significant of these.

Body of report
In the body of the report, each chapter should start on a new page. Chapter headings should appear more important than section headings. This can be achieved for example by the use of different font sizes and attributes. Full direction is given in the project lectures. The following usually have one or more chapters devoted to them.

Development of E-Commerce

2008-11-19T06:27:00.000-08:00

E-commerce covers any form of business transaction or information exchange that is executed using any form of information and communications technology. This embraces business-to-business; business-to-consumer; and government-to-nation; as well as exchange of tools like the Internet and the World Wide Web, intranets, extranets, electronic mail and Electronic Data Interchange. (UK’s e-centre)

· Brief history of E-Commerce;
§ look at what drives E-Commerce;
§ look at the components of an E-Commerce system;
§ list the range of E-Commerce techniques; identifying them within different business contexts;
§ start to look at the impact of E-Commerce on the organisation.

· The application of advanced information technology to increase the effectiveness of the business relationships between trading partners. (Automotive Industry Action Group in North America)

The enablement of a business vision supported by advanced information technology improves efficiency and effectiveness within the trading process. (E-Commerce Innovation Centre at Cardiff University)

The development of E-Commerce in the context of technological developments of the IT world today;

As the current environment provides affordable, more powerful and user-friendly systems, this has promoted the need of a system as a tool provider for business.

The development of EDI (Electronic Data Interchange) brought about data to transfer from one system to another. EDI was widely used in the 1980s and early 1990s. The latter developments were of the X.400 and the Internet.

2.0 Electronic commerce (E-commerce)

· The process of buying, selling, transferring, or exchanging products, services and/or information via computer networks, including the Internet

· The origins of e-commerce first started with innovations such as electronic fund transfer (EFT) in which funds could be routed electronically form one organisation to another

· Then came Electronic Data Interchange (EDI), a technology used to electronically transfer routine documents, which expanded electronic transfers from financial transactions to other types of transaction processing such as ordering

· EDI required having expensive dedicated and private lines between the trading parties

· Internet and WWW overcome the shortcomings of EDI

3.0 Electronic Business

· A broader definition of EC, includes not just the buying and selling of goods and services, but also servicing customers, collaborating with business partners, and conduction electronic transactions within an organisation.
· E-Business is the use of the Internet and other information technologies to support commerce and improve business performance.
· Some view e-business as comprising those activities that do not involve buying and selling over Internet, such as collaboration and intrabusiness activities.

4.0 Types of EC organisations

· Brick and Mortar Organization - Old-economy organizations that perform most of their business off-line, selling physical products by means of physical agents. Purely physical organization.
· Virtual (Pure-Play) Organization – Organization that conduct their business activities solely.
· Click and mortar organization – organization that conduct some e-commerce activities, but do their primary business in the physical world.

5.0 World Wide Web

· Created in the early 1990s Tim Berners-Lee
· Software that allows users to exchange information as it was designed to help scientists share online information using a single, unified interface.
· Mid-1993, Marc Andressen, an undergraduate of University of Illinois, wrote a program called Mosaic, which made using the web as easy as pointing and clicking at pictures and underlined words
· Mosaic was the first graphical browser that was launched with 150 websites holding a few thousand web-pages.
· 1995 there were about 10,000 sites, a number that had grown to 4 - 5 m by mid-1999.
· Commercial use of the Internet has skyrocketed, with companies using the Internet to communicate with each other, with their customers, with their partners and with their suppliers.
6.0 Electronic markets

Classification of EC by the nature of the transactions / interactions:
1. Business-to-business (B2B) – all of the participants are businesses or other organizations e.g suppliers

2. Business-to-Consumer (B2C) / e-tailing – includes retail transactions of products and services from businesses to individual shoppers

3. Business-to-business-to-consumer (B2B2C) – a business provides some product or service to a client business that maintain its own customers

4. Consumer-to-business (C2B) – individuals who use the Internet to sell products or services to organisations, or individuals seek sellers to bid on products or services they need

5. Consumer-to-consumer (C2B) - consumers ell directly to other consumers

6. Peer-to-peer applications – technology that enables networked peer computers to share data and processing with each other directly, can be used in C2C, B2B, and B2C ecommerce

7. Mobile-commerce (m-commerce) – e-commerce transactions and activities conducted in a wireless environment

8. Intra-business EC – includes all internal organisational activities that involve the exchange of goods, services, or information among various units and individuals in an organisation

9. Location-based commerce (l-commerce) – m-commerce transactions targeted to individuals in specific locations, at specific times

10. Business-to-employees (B2E) – organisations deliver services, information or products to its individual employees

11. Collaborative commerce (c-commerce) – individuals or groups communicate or collaborate online

12. E-learning – online delivery of information for the purposes of training or education

13. Exchange-to-exchange (E2E) – electronic exchanges formally connect to one another for the purpose of exchanging information

14. E-government – a government entity buys or provides goods services, or information to businesses (G2B)or individual citizens (G2C)

7.0 Benefits

· Global reach – expands the marketplace to national and international markets. With minimal capital outlay, a company can easily and quickly locate the best supplier, more customers, and the most suitable business partners worldwide.
· Cost reduction – decrease the cost of creating, processing, distributing, storing, and retrieving paper-based information.
· Supply chain Improvements – supply chain inefficiencies, such as excessive inventories and delivery delays can be minimized with EC.
· Extended hours – 24/7/365 the business always open on the Web, with no overtime or other extra costs.

8.0 Limitations

· costs of a technological solution
· some protocols are not standardized around the world
· reliability for certain processes
· insufficient telecommunications bandwidth
· Software tools are not fixed but constantly evolving (ie. Netscape 3,4,4.7,4.75 etc.)
· integrating digital and non-digital sales and production information
· access limitations of dial-up, cable, ISDN, wireless
· some vendors require certain software to show features on their pages, which is not common in the standard browser used by the majority
· Difficulty in integrating e-Commerce infrastructure with current organizational IT systems
9.0 E-Marketplace

An online marketplace where buyers and sellers meet to exchange goods, services, money or information.
E-markets may be supplemented by interorganizational or intraorganizational information systems.

The Internet has had such a huge impact on the world (in business, media and society) that it is easy to overlook the technology that preceded it, that enabled it and that has evolved subsequently. In eCommerce terms, though, this does not mean that this technology is any less valid. Remember, we are trying to find the right tools for the right job.

Networks
Networks are electronic/data highways which link computers together for the purpose of sharing resources. They are characterised by:

• the type of data transmission technology they use;
• whether they carry voice, data, or voice and data;
• whether they are public or private (i.e. who can use them);
• the nature of connection - dial-up, dedicated or virtual connections;
• the types of physical links (such as optical fiber, coaxial cable, and copper wire).

The type of data transmission refers to the protocol they use, i.e. the set of rules for communicating that the end points in a connection use when they exchange signals. Both endpoints must understand and observe the protocol. The Internet uses TCP/IP protocols, which includes TCP (Transmission Control Protocol) and IP (Internet Protocol), HTTP, FTP and other protocols, each with a defined set of capabilities.

Local Area Networks (LANS)
LANs link a number of computers by relatively short lengths of cable, usually within the same room or building . Typically, a more powerful computer, called a server, will serve data and applications to a number of desktop PCs. Due to the short length of the cables, data transmission is very fast (MegaBits or even GigaBits per second). Company LANs are usually controlled by a member of the IT department called the network administrator.
It is important to recognise LANs as part of the communications infrastructure because they are often the basis of a company's IT systems. As such, any implementation of eCommerce will require integration of the LAN with external communications media. A LAN that uses Internet.Protocols is, essentially, an intranet, and can support applications run on the Internet if appropriate server software is installed.
The purpose of an intranet is to allow everyone to share information and facilitate group work processes. Like any other network, it holds file directories and allows resource sharing. Intranets are still very much in their infancy as regards the level of sophistication around the types of applications and information held on them. According to recent research completed by InformationWeek the most common applications on intranets are policy and procedure manuals, document sharing and corporate phone directories.
The intranet must have a firewall to prevent unauthorised access from outside the company. Firewalls are hardware/software combinations that allow people from outside an intranet to access data on the Internet, but keep intruders from getting onto the intranet. Depending on how secure a site needs to be and how much time, money and resources can be spent on a firewall, there are many kinds that can be built. Most of them, however, incorporate the following elements:
• proxy servers;
• routers;
• bastion hosts.

Wide Area Networks (WANs)
WANs connect a number of computers, or LANs using long-distance connections. The connections may be along private cables, microwave or satellite links or may be leased from a network provider, such as an Internet Service Provider (ISP) or a telecoms operator. A WAN may contain a number of switching and relaying computers called 'nodes' or 'gateways'. A connection between two major nodes is called a 'backbone'. The Internet itself is a very large WAN. The extension of a simple LAN to the WAN is also the basis for the similar extension of the concept of the intranet to an extranet, which is a key component of business-to-business eCommerce. Essentially an extranet is a private network that uses the Internet protocols and the public telecommunication system to securely share part of a business's information or operations with suppliers, vendors, partners, customers, or other businesses. An extranet can be viewed as part of a company's intranet that is extended to users outside the company. Therefore, the same benefits that Internet technologies have brought to the Internet and to corporate intranets are now being made available to accelerate business between businesses.

An extranet requires security and privacy. These require firewall server management (in much the same way as intranets) and, increasingly, the use of Virtual Private Networks (VPN's - see below) that are able to tunnel securely through the public network.

The reasons why extranets are, potentially, so important to the area of business-to-business eCommerce, are that they allow organisations to:

• exchange large volumes of data using EDI;
• share product catalogues exclusively with wholesalers or distributors;
• collaborate with other companies on joint development efforts;
• jointly develop and use training programs with other companies;
• provide or access services provided by one company to a group of other companies, such as an online banking application managed by one company on behalf of affiliated banks;
• share news of common interest exclusively with trading partner companies.

Virtual Private Networks
Historically, organisations that needed to construct networks that would serve multiple sites, or maybe allow communication with their clients or suppliers, would achieve this by constructing a virtual private network,or VPN.

With the advent of the Internet, along with relatively cheap broadband access technologies, interest in constructing VPNs across the Internet has grown considerably because it has the potential to offer a VPN service at significantly lower cost than would be the case with networks constructed from dedicated leased lines. However, the very public nature of the Internet means that, although it is possible still to construct trusted VPNs in this environment, many users require a higher degree of assurance that their communications over the VPN will be secure. Hence, this has given rise to the use of technologies that allow secure VPNs to be constructed. The basic concept behind a secure VPN is that all communications taking place across the VPN are encrypted, thus preventing the data from being read in any meaningful form, even if a potential eavesdropper is able to examine the data packets being transmitted on the network. The devices communicating over the network, or the network users, or both, may well also need to be authenticated, to ensure that only trusted individuals or equipment can be attached to the network. Most current implementations of secure VPNs are based on a family of encryption technologies known as IPSec, which is used to construct a secure 'tunnel' across the Internet that can carry the client's data.

VPN technology is accessible to business users in a variety of forms. The telecommunications service providers have offered trusted VPN services for a number of years and, increasingly, are also offering secure VPN services. In both cases, the offering is a managed service, having the advantage of off-loading the maintenance and management of the network from the user. Perhaps the most interesting aspect of secure VPNs is that it is possible for these services to be provided and managed by the businesses that use them. As they rely on encryption technology that can be installed either as software in a PC or as add-ons to existing LANs, VPN services can potentially be used by all sizes of business user, from the SME up to the multi-national.
VPNs can significantly improve the security of communication within a distributed organisation. This can be important for:

• Internal communications within the organisation;
• Communications with client or trading partners, where confidentiality of commercially sensitive information may be a requirement;
• Providing secure networking for home workers.

The same secure VPN technology can also be applied as a means of overcoming the present shortcomings in wireless LAN security; if all information transmitted over the wireless LAN is properly encrypted using the IPSec mechanisms, it is no longer a concern that an eavesdropper might be able to 'see' the data packets being communicated, since it will be impossible to decrypt the data. Secure VPNs can, in many ways, be viewed as a means of making the other networking technologies safer to use in a commercial environment; hence, coupled with the other technologies mentioned in earlier sections, VPNs become an essential factor in delivering the benefits that can accrue from these technologies.
A major benefit with managed VPN services is that they significantly reduce the costs associated with constructing and managing a wide area data network. This can be significant for all sizes of business. Even the larger multinationals often cannot afford the expense of running a truly private WAN, whereas the established telecommunications suppliers can offer a managed service at a much more affordable cost.
Virtual private network technology is not only available today from companies specialising in VPNs, but also from operating system vendors (e.g. Microsoft) and traditional firewall vendors. There is limited interoperability between products from different vendors today, since standards are only now being finalised. Therefore, the user is likely to need software from the same vendor for both end points of the tunnels. The key standard that is emerging is IPsec (secure IP), whilst others include SOCKS and Layer 2 Tunneling Protocol (L2TP). The L2TP standard combines attributes of Microsoft's Point to Point Tunneling Protocol (PPTP) and Cisco's L2F (layer 2 forwarding.)
The development of E-Commerce in the context of business developments
Communication

1. Options:
• Telephone: dial-up or leased line
• ISDN: basic rate or primary rate
• Value Added Networks
• X.400: ISO standard secure messaging
• Networks: local area networks, wide area networks or intranets
• Internet: messaging, file transfer, Telnet, World Wide Web, XML

2. Standards:
• Standards are the means by which data is sent in an agreed format by eCommerce trading partners.
• In Electronic Data Interchange (EDI), standards pertain specifically to the syntax used to prepare messages for exchange. They enable, for example, one accounts system to understand an electronic version of an invoice sent out by another accounts system because the relevant pieces of data (e.g. invoice number) are always located in the same part of the message.
• In the case of EDI, these standards are generally nationally and
• The means which data is sent in an agreed format by E-commerce trading partners.
E.g.:
• EDI: syntax used to prepare message for exchange
• Gif and JPG: graphic standards
• World Wide Web:HTML, PERL, Javascript, Java, Software

3. The e-commerce software function includes:
• Data extraction from relevant application or data entry
• Data encoding to agreed standard format
• Data transmission to recipients.
• Data receipt by recipients.
• Data decoding for internal applications.
• Data insertion into relevant applications

Business-to-Business E-commerce
Key areas in B2B e-commerce:
• Electronic Data Interchange (EDI)
• Enhanced messaging: e-mail, voice-mail, fax
• Teleconferencing
• Integrated Systems: intranets/extranets, database publishing, workflow

Supply Chain E-commerce

1.0 Defining E-Commerce

• Key areas in B2B e-commerce:
1. Stock control
2. Just-in-time delivery
3. Transportation
4. Warehouse management
5. Automatic Identification: Barcodes, Transponders
Business-to-Consumer E-commerce
B2C e-commerce application includes:
1. Database application
2. Kiosks
3. Internet store fronts
4. Downloadable software and software support
5. Internet auctions
6. Advertising on the Internet
7. Interactive TV

Technology System

2008-11-19T05:47:00.000-08:00

THE COMPUTER SYSTEM AND HOW IT PROCESS DATA

A computer system is a group of machines, or hardware that accepts data, process it, and display information. The main reason for using computer system is to process data quickly and efficiently so that the information obtained is timely, meaningful, and accurate.

A computer system performs its information processing operations under the control of sets of instructions called programs. Computers read incoming data called input, process the data, and display outgoing information called output.

Data itself consists of raw facts, data that is processed or operated to produces structured, meaningful information. Information processing is a set of procedures used to operate on data and produce meaningful results.

Computer system consists of the following components; input devices, main memory and the central processing unit, output devices, and secondary storage devices.

INPUT DEVICES READ INCOMING DATA

There are many different types of input devices; keyboards, disk drives, page scanner, optical reader, and voice recognition units, to name a few. Each input device reads a specific form of data; for example, keyboard transmits typed characters whereas scanners “read” typed or handwritten characters from documents or images from graphs, photos, or drawings. Any input device converts data into electronic pulses that are transmitted to the CPU for processing.

MAIN MEMORY AND CENTRAL PROCESSING UNIT

Main memory stores programs and data for processing and the Central Processing Unit, or CPU, controls all computer operations. The CPU reads data into main memory from an input device, processes the data according to program instructions, and produces information by activating an output device.

The CPU is the “brains” of the computer system. The unit that houses main memory and the CPU must be linked by cables (or by communication channels such as telephone lines) to all input and output devices in the computer system.

The program, or set of instructions for processing data, is read into main memory by the CPU before data can be entered and processed and information generated.

OUTPUT DEVICES PRODUCE OUTGOING INFORMATION

Each output device in a computer system accepts information from main memory under the control of the CPU, and converts it to an appropriate output form.

A printer, for example, is an output device that prints reports or graphics based on information that the CPU has processed and produced. Similarly, a video monitor is an output device that displays both text and graphics on a screen.

STORING PROGRAMS AND DATA FOR FUTURE PROCESSING

Once you turn off a computer, the data and instructions operated on by the CPU are lost. For this reason, separate storage devices are needed to keep the data and instructions in electronic form for then to be conveniently used again and again. Disks are common storage media for PCs and for larger computer systems.

A computer has two types of storage, namely main memory or PRIMARY STORAGE and external storage or called SECONDARY STORAGE. Main Memory contains computer program and the data currently being processed. It is volatile (i.e. it loses its contents when power supply is switched off). Secondary Storage stores data and programs that are not currently required by the CPU. It is transferred to the Main Memory when required. It is non-volatile (i.e. it retains data even though power supply is switched off)

SOFTWARE MAKES IT WORK

Before computer hardware can actually read data, process it, and produce information, it needs a set of instructions – a program – that actually controls the CPU operations. Programs, like data, are read into main memory under the control of the CPU.

We say that computers are stored-program-devices because they require a set of instructions to be stored in the computers main memory before data can be processed.

Computer professionals called programmers write programs for each user need or application area. The total set of programs that enables the computer system to process data is referred to as software.

TYPES OF SOFTWARE

Computers require two types of software; System Software to monitor and supervise the overall operations of the computer system and Application Software to manipulate input data and provide users with meaningful output information.

SYSTEM SOFTWARE

Computers use a series of control programs, called the operating systems, that moves data in and out of main memory and monitors the running of application programs.
The operating system is the primary component of system software. Some computers have built-in operating system, but these cannot be easily changed or updated.

Most computer manufacturers either provide their own operating system, usually on disk, or allow users to purchase disks containing the more popular operating systems.

Operating systems interact with users by means of a user interface. Some operating systems, especially those for larger computer systems, are text based and require the user to learn a set of commands (command line interface)

Some operating systems for PCs like the Macintosh operating systems, permit users to select commands from graphic symbols, or icons, displayed on the screen. Text-based operating systems, like DOS (Disk Operating System) for IBM and IBM compatibles computers, can work in conjunction with graphical user interfaces like windows, which make them easier to use or more user friendly.

APPLICATION SOFTWARE

Application programs are designed to satisfy user needs by operating on input data to perform a given job, for example, to prepare a report, update a master payroll file, or print customer bills.

Typically, application programs are acquired in one of two ways; Package programs purchased off-the-shelf from a software retailer or; Custom programs designed especially for the unique needs of an individual or an organization

Packaged programs allow limited customization, but they really are intended to be used as is by a broad range of users. Although they may not meet all aspects of every users need, application packages are inexpensive compared to custom programs and are supplied with comprehensive user reference manuals called documentation.

Custom software, on the other hand, is written by programmers within an organization, by outside consultants, or by self-employed programmers. Custom programs are designed to meet the precise needs of users, but they are very time consuming and costly to develop.

THE COMPUTER GENERATIONS

Since the 1940’s, four generations of computers have evolved. From the first to the fourth, the trend has been to produce more powerful, less expensive, smaller and more reliable computer systems.

First generation

The first commercial electronic computer was UNIVAC 1 (Universal Automatic Computer). This machine was developed specifically for scientific and military purposes, but was dedicated to business data processing applications.

The characteristic that distinguished first generation computers from subsequent machines was the use of vacuum tubes to control internal operations. Vacuum tube un-reliable, generate a lot of heat, required air-conditioning system.

Binary notation was used instead of decimal notation. All instructions and information were stored in the computer as 1s and 0s, which corresponds to the electronic conditions ‘on’ and ‘off’.

Drawbacks:

They took several minutes to ‘warm up”. When they were completely warmed up, they became quite hot. Early computers used thousands of vacuum tubes. They occupied the whole rooms and required an enormous amount of electric current to keep them going.

Second generation

In the late 1950s, tiny, solid-state transistors replaced vacuum tubes in computers. The elimination of vacuum tubes greatly reduces generated heat and made possible the reduction in the size of the developed computers.

This generation of computer also uses magnetic cores for representing data in computer. Because cores were far smaller than vacuum tubes, internal storage capacity becomes greater even though the actual size of second generation computers was sharply reduced.

As about the same time, in the early 1960’s, magnetic tape and disks began to be widely used by auxiliary storage. As a result of these developments, a significant increase in the speed and processing capability of computers was achieved.

Third generation

Further technological advancement in electronics brought further reductions in size, greater reliability and speed and lower costs computer. Integrated circuits (ICs) replace the transistors and this marked the development of third generation computers.

This development is known as large-scale integration, or LSI, and is refer to the ability to compress large numbers of Integrated circuits, or transistors, on a single silicon chip. For example, 5,000 transistors can be placed on a chip to produce a digital watch.

Fourth generation

Fourth generation computers continue to be characterized by chips that can contain increasing numbers of items. Now, over 1 million items can be stored on a single chip. This further miniaturization of components, commonly referred to as Ultra-large-scale integration (ULSI), result in increased speed, greater reliability, and enormous storage capacities for current computers.
Microprocessor

The Intel Corporation was the first company that developed the microprocessor, or computer on the chip. One chip could contain all the circuits necessary to perform the basic functions of an entire computer. Microprocessors are not only used in fourth generation computers, but for wide variety of products including automobiles, sewing machines, microwave ovens, electronics games and so on.

The microprocessor was a general purpose computer that could be programmed to do any number of tasks, from running a watch to guiding a missile. No longer was it necessary to design circuit specially for each intended purpose. Manufacturers could now make a single type of microprocessor and sell it to other manufacturers, who would use them for thousands of different applications.

The Fifth generation computers

Unlike all other generation computers, this generation of computers is close at hand and is characterized by the use of the technique used to reduce complex programming. This technique used is known as Artificial Intelligence (AI). The Japanese, who are currently at the forefront in the development of fifth-generation computers, refer to them as truly “intelligent machine”.

Classification of Computers

Computers can be loosely categorized according to their capacity for processing data. Large computers called mainframes are used by such customers as banks, airlines, and large manufacturers to process very large amounts of data quickly.

The most powerful and expensive computers are called supercomputers. Minicomputers, which are widely used by colleges and retail businesses, have become increasingly similar to main--frames in terms of capacity. The largest and most expensive minicomputers are called super minis.

The smallest computers-such as desktop office computers or-home computer are called personal computers, or sometimes microcomputers. Super micros, or work-stations, combine the compactness of a desktop computer with power that almost equals that of a mainframe. As computer technology-changes, distinctions between types of computers will also change.

A centralized computer system does all processing in one location. In a decentralized system, -the computer itself and some storage devices are in one place, but the devices to access the computer are somewhere else. Such a system requires data communications - the exchange of data over communications facilities.

In a distributed data -processing system, a local office usually uses its own small computer for processing local data but is connected to a central headquarters computer for other purposes.

Often organizations use a network of personal computers, which allows users to operate independently or in cooperation with other computers-exchanging data and sharing resources. Such a setup, often called a local area network (LAN), can even connect personal computers to a mainframe computer to form a micro-to mainframe link, in which users can obtain data from the mainframe and analyze it on their own personal computers.

People and Computers

People are vital to any computer system. An organization's computer resources department-often called Management Information Services (MIS) or Computer Information Systems (CIS), Computing 5cr-vices, or Information Service-includes data entry operators (who prepare data for processing), computer operators (who monitor and run the equipment-librarians who catalog disks and tapes), computer programmers (who design, write, test, and implement pro grams), systems analysts (who plan and design entire systems of programs), and a chief information officer (who coordinates the MIS department).

In general, a distinction is made between computer professionals, who provide computer systems, and users, who use the systems. However, in a development called the end-user revolution, users have become increasingly knowledgeable about computers and less reliant on computer professionals.

COMPUTER USAGE IN COMPANY

Reception

Before the installation of a computerized telephone system, a full-time operator was required to answer the telephone and direct the calls. Now, the computerized telephone system routes the calls to the appropriate person or department. If a caller does not want to leave a voice message or requests to talk to an operator, the call is routed to the receptionist. The receptionist can use the computer to determine the location of an employee. When employees leave their work areas for a meeting, lunch, or to travel away from the office, they record their destinations or reasons for being away using their computers. The employees can also record any special instructions to the receptionist, such as when they will return or to please hold their calls. If a caller wishes to leave a voice message, the computerized telephone system can play it back for the employee when he or she returns or calls in for messages.

Sales

For example of a company where sales department consists of two groups: (1) in-house sales representatives, who handle phone-in and mail-in sales orders and the field sales force, who make sales calls at customer locations. The in-house sales staff uses headset telephones so their hands are free to use their computer keyboards. Using the computer while they are on the telephone with a customer allows them to check product availability and the customer's credit status. A computer program also recommends products that complement the products ordered by the customer and displays information on special product promotions.

(2) Outside sales representatives use notebook computers and special communications equipment and software to communicate with the Dalton main office. As with the in-house sales staff, they also can check product availability and customer credit status. If they receive a customer order, they can enter it into the Dalton computer system while they are still at the customer site. In addition, the field sales representatives can use the e-mail capability to check for or send messages.

Marketing

The marketing department uses the computer system for a number of purposes. Desktop publishing, drawing, and graphics software are used to develop all marketing literature. Product brochures on bicycle parts, advertising materials, and product packaging are all produced in-house, saving considerable time and money.

The customer service representatives all have computers that allow them to record a variety of customer inquiries. Recording the nature of each customer service inquiry provides for better follow-up (less chance of forgetting an unresolved inquiry) and enables the company to summarize and review why customers are calling. This helps the company identify and resolve potential problems at an early stage. The marketing department also uses a calendar program to schedule product promotions and attendance at trade.

Shipping and Receiving

The shipping and receiving department uses the computer system to enter transactions that keep a company’s inventory records accurate. Inventory receipts are first checked against computer records to make sure that the company receives only what was ordered. If the received goods match what was ordered, only a single entry has to be made to update the on-hand inventory and purchasing records.

Shipping transactions are also efficient. If all requested items are in stock, only a single entry is required to decrease the inventory and create the information that will be used to prepare the billing invoice. Shipping information, such as the method and time of shipment, can be added to the transaction record so the computer system can be used to provide an up-to-the-minute status of the customer's order.

Manufacturing

The manufacturing department uses the computer to schedule production and to record the costs of the items produced. Special manufacturing software matches the availability of production resources such as people, machines, and material against the desired product output. This information allows certain companies schedule production efficiently and tells them when and how much to buy of the raw materials they need to produce their products.

Actual labour, material, and machine usage is recorded on the manufacturing floor using special workstations designed to be used in industrial environments. This information is entered into the computer system automatically to update inventory, production, payroll, and cost accounting records.

Product Design

The product design department uses computer-aided design (CAD) software to design new products. CAD software allows the designers to create and review three-dimensional models of new products on the computer before expensive models are required. If a design is approved, the CAD software can automatically produce a list of the required parts.

Accounting

The accounting department is one of the largest computer system users. Many of the accounting records are the result of transactions entered in the user departments, such as shipping and receiving and manufacturing. These records are used to pay vendor invoices, bill customers for product sales, and process the employee’s payroll.

The accounting transactions are summarized automatically to produce financial statements, which are used internally to monitor financial performance and given to outside organizations such as banks.

Human Resources

The human resources department uses the computer system to keep track of information on existing, past, and potential employees. Besides the standard information required for payroll and employee benefits, the system keeps track of employees job skills and training. This information enables the human resources department to review the records of existing employees first when a new job.

Information Systems

A primary responsibility of the information systems department is to keep the existing system running and determine when and if new equipment or software is required. To help answer these questions, the information systems personnel use diagnostic and performance measurement software that tells them how much the system is being used and if system problems are being encountered.

A systems analyst works with users to design custom software for user applications for which application software packages do not exist. A computer programmer then uses this design to write the program instructions necessary to produce the desired processing results and output.

Executive

The senior management staff of a company, for example (the president and three vice presidents) use the computer as an executive information system (EIS). The EIS summarizes information such as actual sales, order backlog, number of employees, cash on hand, and other performance measures into both a numeric and graphic display.

The EIS is designed specifically for executives who may not work regularly with computers and want only to see summarized information.

Summary of uses of computer of a company
The computer applications just discussed are only some of the many potential uses of the computers within a company like vehicle parts manufacturer. In addition, employees in each of the departments can use the computer for preparing correspondence, project and task management, budgeting, and sending messages via electronic mail. As shown in the Dalton Corporation example, computers are used throughout an organization. Employees use computers to perform a variety of tasks related to their job areas. Because of the widespread use of computers, most organizations prefer to hire employees with computer experience and knowledge.

Basic Concept

2008-11-04T04:27:00.000-08:00

BASIC CONCEPT OF INFORMATION TECHNOLOGY

Topic list
1 Organisational information requirements 1(a)
2 Business strategy and information systems strategy 1(a)
3 Developing a strategy for information systems and information technology 1(a)
4 Critical success factors 1(a)

Introduction
Welcome to Paper 2.1 Information Systems. This Study Text follows the structure of the officialACCA syllabus and study guide wherever possible.
The front page of each chapter provides syllabus and study guide references showing the areascovered within the chapter.
We start with a look at the concept of business strategy and strategic planning. Later in thischapter we examine the relationships between business strategy, information systems (IS) andinformation technology (IT).

Study guide
Part 1.1 - Business strategy and IS/IT alignment
• Explain an approach that an organisation may follow to formulate its strategic businessobjectives
• Discuss how information systems may be used to assist in achieving these objectives (thisissue is relevant throughout this text)
• Distinguish between a business strategy and an information systems strategy
• Identify responsibility for the ownership of the IS strategy

1 ORGANISATIONAL INFORMATION REQUIREMENTS
1.1 All organisations require information for a range of purposes. These can be categorised asfollows.
• Information for planning
• Information for controlling
• Information for recording transactions
• Information for performance measurement
• Information for decision making

Planning
1.2 Planning requires a knowledge of the available resources, possible time-scales and the likelyoutcome under alternative scenarios. Information is required that helps decision making,and how to implement decisions taken.

Controlling
1.3 Once a plan is implemented, its actual performance must be controlled. Information isrequired to assess whether it is proceeding as planned or whether there is someunexpected deviation from plan. It may consequently be necessary to take some form ofcorrective action.

Recording transactions
1.4 Information about each transaction or event is required. Reasons include:
(a) Documentation of transactions can be used as evidence in a case of dispute.
(b) There may be a legal requirement to record transactions, for example for accountingand audit purposes.
(c) Operational information can be built up, allowing control action to be taken.

Performance measurement
1.5 Just as individual operations need to be controlled, so overall performance must bemeasured. Comparisons against budget or plan are able to be made. This may involve thecollection of information on, for example, costs, revenues, volumes, time-scale andprofitability.

Decision making
1.6 Strategic planning, management control and operational control may be seen as a hierarchyof planning and control decisions. (This is sometimes called the Anthony hierarchy, afterthe writer Robert Anthony.)predicted
1.7 Strategic planning is a complex process which involves taking a view of the organisationand the future that it is likely to encounter, and then attempting to organise the structureand resources of the organisation accordingly.

Strategic information
1.8 Strategic information is used to plan the objectives of the organisation, and to assesswhether the objectives are being met in practice. Such information includes overallprofitability, the profitability of different segments of the business, future market prospects,the availability and cost of raising new funds, total cash needs, total manning levels andcapital equipment needs.

1.9 Strategic information is:
• Derived from both internal and external sources
• Summarised at a high level
• Relevant to the long term
• Concerned with the whole organisation
• Often prepared on an 'ad hoc' basis
• Both quantitative and qualitative
• Uncertain, requiring assumptions to be made regarding the future

Tactical information
1.10 Tactical information is used to decide how the resources of the business should beemployed, and to monitor how they are being and have been employed. Such informationincludes productivity measurements (output per hour) budgetary control or varianceanalysis reports, and cash flow forecasts, staffing levels and profit results within a particulardepartment of the organisation, labour turnover statistics within a department andshort-term purchasing requirements.

1.11 Tactical information is:
• Primarily generated internally (but may have a limited external component)
• Summarised at a relatively low level
• Relevant to the short- and medium-terms
• Concerned with activities or departments
• Prepared routinely and regularly
• Based on quantitative measures

Operational information
1.12 Operational information is used to ensure that specific operational tasks are planned andcarried out as intended.

1.13 In a payroll office, for example, operational information would include the hours worked byeach employee and the rate of pay per hour.

1.14 Operational information is:
• Derived from internal sources
• Detailed, being the processing of raw data
• Relevant to the immediate term
• Task-specific
• Prepared very frequently
• Largely quantitative

The qualities of good information
1.15 'Good' information is information that adds to the understanding of a situation. Thequalities of good information are outlined in the following table.

Quality Example
A ccurate
Figures should add up, the degree of rounding should beappropriate, there should be no typos, items should be allocatedto the correct category, assumptions should be stated foruncertain information.

C omplete
Information should include everything that it needs to include,for example external data if relevant, or comparative information.

C ost-beneficial
U ser-targeted
It should not cost more to obtain the information than the benefitderived from having it. Providers or information should be givenefficient means of collecting and analysing it. Presentation shouldbe such that users do not waste time working out what it means.
The needs of the user should be borne in mind, for instancesenior managers need summaries, junior ones need detail.
R elevant
Information that is not needed for a decision should be omitted,no matter how 'interesting' it may be.

A uthoritative
The source of the information should be a reliable one (not, forinstance, 'Joe Bloggs Predictions Page' on the Internet unless JoeBloggs is known to be a reliable source for that type ofinformation).
T imely
The information should be available when it is needed.
E asy to use Information should be clearly presented, not excessively long,and sent using the right medium and communication channel (e-____ ______ mail, telephone, hard-copy report etc).

Improvements to information
1.16 The table on the following page contains suggestions as to how poor information can beimproved.

Feature Example of possible improvements
Accurate Use computerised systems with automatic input checks rather than manualsystems.
Allow sufficient time for collation and analysis of data if pinpoint accuracyis crucial.
Incorporate elements of probability within projections so that the requiredresponse to different future scenarios can be assessed.
Complete Include past data as a reference point for future projections.Include any planned developments, such as new products.
Information about future demand would be more useful than informationabout past demand.
Include external data.
Cost- Always bear in mind whether the benefit of having the information isbeneficial greater than the cost of obtaining it.
User-targeted Information should be summarised and presented together with relevantratios or percentages.
Relevant The purpose of the report should be defined. It may be trying to fulfil toomany purposes at once. Perhaps several shorter reports would be moreeffective.
Information should include exception reporting, where only those itemsthat are worthy of note - and the control actions taken by more juniormanagers to deal with them - are reported.
Authoritative Use reliable sources and experienced personnel.
If some figures are derived from other figures the method of derivationshould be explained.
Timely Information collection and analysis by production managers needs to bespeeded up considerably, probably by the introduction of betterinformation systems.
Easy-to-use Graphical presentation, allowing trends to be quickly assimilated andrelevant action decided upon.
Alternative methods of presentation should be considered, such as graphsor charts, to make it easier to review the information at a glance. Numericalinformation is sometimes best summarised in narrative form or vice versa.
A 'house style' for reports should be devised and adhered to by all. Thiswould cover such matters as number of decimal places to use, tableheadings and labels, paragraph numbering and so on.

BUSINESS STRATEGY AND INFORMATION SYSTEMS STRATEGY
The relationship between corporate, business and operational strategies is shown in thefollowing diagram.

STRATEGIES INVOLVING MANY FUNCTIONS (EG CHANGE MANAGEMENT,TOTAL QUALITY, RE-ENGINEERING)

Functional/operational strategies; information systems strategy
2.2 Information systems strategy is an example of a functional/operational strategy (althoughin some cases it may have strategic implications). Functional/operational strategies dealwith specialised areas of activity.
Functional area Comment
Information systems A firm's information systems are becoming increasingly important, as an item of expenditure, as administrative support and as a tool forcompetitive strength.
Marketing Devising products and services, pricing, promoting and distributing them, in order to satisfy customer needs at a profit.
Production Factory location, manufacturing techniques, outsourcing etc.
Finance Ensuring that the firm has enough financial resources to fund itsother strategies.
Human Secure personnel of the right skills in the right quantity at the rightresources time.
R&D New products and techniques.

Information systems and business strategy
2.3 It is widely accepted that an organisation's information system should support corporateand business strategy. In some circumstances an information system may have a greaterinfluence and actually help determine strategy. For example:
(a) IS/IT may provide a possible source of competitive advantage. This could involve newtechnology not yet available to others or simply using existing technology in a differentway.
(b) The information system may help in formulating business strategy by providinginformation from internal and external sources.
(c) Developments in IT may provide new channels for distributing and collectinginformation, and /or for conducting transactions eg the Internet.
Accountants and IT managers areseen as scorekeepers andadministrators rather than as abusiness partner during thestrategic planning process

Change from cost-orientated to Imarket-orientated ie development \of more effective strategic planningsystems

VISION AND REALITY
3.1 A company that has a vision of its own future, and some idea of how information
technology can be used to turn that vision into reality, may be able to use new technologiesfor strategic advantage.

3.2 One approach to creating a vision is to adopt a familiar three step approach, involvinganswering three questions about the organisation.

• Where are we now?
• Where do we want to be?
• How will we get there?

3.3 The first question can be answered using standard techniques such as a strengthsweaknesses, opportunities, threats (SWQT) analysis. This approach ensures that bothinternal and external factors are considered. We cover SWOT analysis in the context ofinformation systems development in Chapter 6.

3.4 Answering the second question requires vision. This does not have to be a continuation in
the organisation's current direction. It must be challenging, attainable and communicatedto those who will implement it.

3.5 Once this has been done, the strategy (in answer to the third question) can be defined.

3.6 A second approach takes the view that insiders are too tied to 'the way we do things now'and recommends the involvement of outsiders. An outsider may be able to more readilyanticipate dramatic shifts which might occur in the future. Additionally, an outsider doesnot have the insider's investment in maintaining the status quo.

Information systems, strategy and competitive advantage
3.7 It is now recognised that information can be used as a source of competitive advantage. Therealisation that information (and therefore information systems and informationtechnology) may be a source of competitive advantage and be key to achievingorganisational goals, has led to increased emphasis on the importance of formalmanagement strategies and plans for information and information systems.

3.8 A strategy is needed for areas in which decisions have the potential to have a major impacton an organisation. Many organisations have recognised the importance of information anddeveloped an information strategy, covering both IS and IT.

3.9 In commercial organisations it could be argued that one of the main aims of any strategy iscompetitive advantage - as success ultimately depends upon doing something better thancompetitors do. Business objectives, if achieved, should result in competitive advantage inone or more areas. This process is contributed to by ensuring the organisation's strategy forinformation and information systems is tied to business objectives.
(a) The corporate strategy is used to plan functional business plans which provideguidelines for information-based activities.
(b) On a year by year basis, the annual plan would try to tie in business plans withinformation systems projects, perhaps through a steering committee.

Information systems strategy
3.10 An IS strategy therefore deals with the integration of an organisation's informationrequirements and information systems planning with its long-term overall goals (customerservice etc). IS strategy is formulated at the level of business where specific customer needsetc can be delineated. It deals with what applications should be developed, and whereresources should be deployed.

3.11 The information technology (IT) strategy leads on from the IS strategy above. It dealswith the technologies of:
• Computing
• Communications
• Data
• Application systems

3.12 This provides a framework for the analysis and design of the technological infrastructureof an organisation. This strategy indicates how the information systems strategies that relyon technology will be implemented.
Why have an IS/IT strategy?

3.13 A strategy for information systems and information technology is justified on the groundsthat IS/IT:
• Involves high costs
• Is critical to the success of many organisations
• May be utilised as part of the commercial strategy in the battle for competitiveadvantage
• Can significantly change the business environment
• Affects all levels of management
• Affects the way management information is created and presented
• Requires effective management to obtain the maximum benefit
• Involves many stakeholders inside and outside the organisation

IS/IT is a high cost activity
3.14 Many organisations invest large amounts of money in IS, but not always wisely.

3.15 The unmanaged proliferation of IT is likely to lead to expensive mistakes. Two key benefitsof IT - the ability to share information and the avoidance of duplication - are likely to belost.

3.16 All IT expenditure should therefore require approval to ensure that it enhances rather thandetracts from the overall information management strategy.

IS/IT is critical to the success of many organisations
3.17 When developing an IS/IT strategy a firm should assess how important IT is in theprovision of products and services. The role that IT fills in an organisation will varydepending on the type of organisations. IS/IT could be:
• A support activity
• A key operational activity
• Potentially very important
• A strategic activity (without IT the firm could not function at all)
• A source of competitive advantage

IT can significantly change the business environment
3.18 IT is an enabling technology, and can produce dramatic changes in individual businessesand whole industries. For example, the deregulation of US airline system encouraged thegrowth of computerised seat-reservation systems (eg SABRE, as used by American Airlineswhich always displayed American Airlines flights preferentially). IT can be both a cause ofmajor changes in doing business and a response to them.

IT affects all levels of management
3.19 IT has become a routine a feature of office life, a facility for everyone to use. IT is nolonger used solely by specialist staff.

IT and its effect on management information
3.20 The use of IT has permitted the design of a range of Management Information Systems(MIS). Executive Information Systems (EIS), Decision Support Systems (DSS), and expertsystems can be used to enhance the flexibility and depth of MIS. (We look at different typesof information system in Chapter 2.)

3.21 IT has also had an effect on production processes. For example. Computer IntegratedManufacturing (CIM) changed the methods and cost profiles of many manufacturingprocesses. The techniques used to measure and record costs have also adapted to the use ofIT.

IT and stakeholders
3.22 Parties interested in an organisation's use of IT are as follows.
(a) Other business users - for example to facilitate Electronic Data Interchange (EDI).
(b) Governments - eg telecommunications regulation, regulation of electronic commerce.
(c) IT manufacturers looking for new markets and product development. User-groupsmay be able to influence software producers.
(d) Consumers - for example as reassurance that product quality is high, consumers mayalso be interested if information is provided via the Internet.
(e) Employees - as IT affects work practices.

3.25 An IS strategy therefore deals with the integration of an organisation's informationrequirements and information systems planning with its long-term overall goals (customerservice etc). IS strategy deals with what applications should be developed and whereresources should be deployed.

3.26 The information technology (IT) strategy leads on from the IS strategy above. It dealswith the technologies of:
• Computing
• Communications
• Data
• Application systems

3.27 This provides a framework for the analysis and design of the technological infrastructureof an organisation. This strategy indicates how the information systems strategies that relyon technology will be implemented.

Establishing organisational information requirements
3.28 The identification of organisational information needs and the information systemsframework to satisfy them is at the heart of a strategy for information systems andinformation technology.

3.29 The IS and IT strategies should complement the overall strategy for the organisation. Itfollows therefore that the IS/IT strategy should be considered whenever the organisationprepares other long-term strategies such as marketing or production.

Earl's three leg analysis
3.30 The writer Earl devised a method for the development of IS strategies. His methodidentified three legs of IS strategy development:
• Business led (top down emphasis, focuses on business plans and goals)
• Infrastructure led (bottom up emphasis, focuses on current systems)
• Mixed (inside out emphasis, focuses on IT/IS opportunities)

4 CRITICAL SUCCESS FACTORS
4.1 The use of critical success factors (CSFs) can help to determine the informationrequirements of an organisation. CSFs are operational goals. If operational goals areachieved the organisation should be successful.

4.2 The CSF approach is sometimes referred to as the strategic analysis approach. Thephilosophy behind this approach is that managers should focus on a small number ofobjectives, and information systems should be focussed on providing information to enablemanagers to monitor these objectives.

4.3 Two separate types of critical success factor can be identified. A monitoring CSF is used tokeep abreast of existing activities and operations. A building CSF helps to measure theprogress of new initiatives and is more likely to be relevant at senior executive level.
• Monitoring CSFs are important for maintaining business
• Building CSFs are important for expanding business

4.4 One approach to determining the factors which are critical to success in performing afunction or making a decision is as follows.
• List the organisation's objectives and goals
• Determine which factors are critical for accomplishing the objectives
• Determine a small number of key performance indicators for each factor

4.5 The determination of key performance indicators for each of these CSFs is not necessarilystraightforward. Some measures might use factual, verifiable data, while others might makeuse of'softer' concepts, such as opinions, perceptions and hunches.

4.6 For example, the reliability of stock records can be measured by means of physical stockcounts, either at discrete intervals or on a rolling basis. Forecasting of demand variationswill be much harder to measure.

4.7 Where measures use quantitative data, performance can be measured in a number of ways.
• In physical quantities, for example units produced or units sold
• In money terms, for example profit, cevenues, costs or variances
• In ratios and percentages

4.8 In general terms Rockart identifies four sources of CSFs.
(a) The industry that the business is in.
(b) The company itself and its situation within the industry.
(c) The environment, for example consumer trends, the economy, and political factors ofthe country in which the company operates.
(d) Temporal organisational factors, which are areas of corporate activity which arecausing concern, for example, high stock levels.

4.9 More specifically, possible internal and external data sources for CSFs include thefollowing.
(a) The existing system. The existing system can be used to generate reports showingfailures to meet CSFs.
(b) Customer service department. This department will maintain details of complaints,refunds and queries.
(c) Customers. A survey of customers, provided that it is properly designed andintroduced, would reveal (or confirm) those areas where satisfaction is high or low.
(d) Competitors. Competitors' operations, pricing structures and publicity should beclosely monitored.
(e) Accounting system. The profitability of various aspects of the operation would be akey factor in any review ofCSFs.
(f) Consultants. A specialist consultancy might be able to perform a detailed review of theorganisation to identify CSFs.

4.11 EXAMPLE
An organisation has an objective to maintain a high level of service direct from stockwithout holding uneconomic stock levels. This is quantified in the form of a goal, whichmight be to ensure that 95% of orders for goods can be satisfied directly from stock, whileminimising total stockholding costs and stock levels. CSFs and KPIs might then beidentified as the following.
CSF KPI
Supplier performance Average order lead time
Stock records reliability Number of discrepancies found
Accurate demand forecasting Difference between forecast and actual demand
CSF approach: strengths and weaknesses4.12
CSF approach - strengths Comment
Takes into accountenvironmental changes
The CSF approach requires managers to examine theenvironment and consider how it influences theirinformation requirements.
Focuses on information
The approach doesn't just aim to establish organisationalobjectives. It also looks at the information and informationsystems required to establish and monitor progress towardsthese objectives.
Facilitates top managementparticipation in systemdevelopment
The clear link between information requirements andindividual and organisational objectives encourages topmanagement involvement in system (DSS, EIS) design.

4.13
CSF approach - weaknesses Comment
Aggregation of individualCSFs
Wide-ranging individual CSFs need to be aggregated into aclear organisational plan. This process relies heavily onjudgement. Managers who feel their input has beenneglected may be alienated.
Bias towards topmanagement
CSFs change often
When gathering information to establish CSFs it is usuallytop management who are interviewed. These managersmay lack knowledge of operational activities.
The business environment, managers and informationsystems technology are subject to constant change. CSFsand systems must be updated to account for change.

Chapter roundup Summary
• Organisations require information for a variety of purposes including
· Planning
· Controlling
· Recording transactions
· Measuring performance
· Decision making
• A strategy is a general statement of long-term objectives and goals and the ways by whichthese will be achieved. Strategic planning is the formulation, evaluation and selection ofstrategies for the purpose of preparing a long-term plan of action to attain objectives.
• Information systems and Information Technology (IS/IT) strategy refers to the long-term planconcerned with exploiting IS and IT either to support business strategies or create newstrategic options.
• IS/IT strategy is an example of a functional/operational strategy, but may have strategicimplications.
• A strategy is needed for IS/IT because these areas involve high costs, are critical to thesuccess of many organisations, can be used as a strategic weapon and affects internal andexternal stakeholders.
• IS/IT are sufficiently important and widespread to require proper planning and managementattention.
• IT developments have increased the amount of information available to organisations. It isimportant to ensure information is useful - that it is of good quality.
• Developing strategy involves taking a number of steps, from setting strategic objectives rightthrough to evaluating actual performance. Three basic issues are the organisation's overallbusiness objectives and in consequence its IS/IT needs, the organisation's current ITusage and the potential opportunities that IT can bring.
• Critical success factors are a small number of key operational goods vital to the success ofan organisation.

The Process of Communication

2008-11-04T04:11:00.000-08:00

A. Learning Objectives:

1. to know what is communication
to know the various barriers of communication

B. Learning Outcomes:

to be able to explain the process of communication
to be to identify the various barriers of communication

C. Sub Topic
The process of communication is divided into :
1. Sender
2. Encode
3. Message
4. Decode
5. Receiver
6. Feedback

D. Sub Topic
The various barriers of communication

The Process of Communication

Every individual needs to communicate in one or the other way. It takes many forms such as writing, speaking and listening. The hard facts are that a manager, however skilled, needs to learn some basic rules to get the message across, clearly. Communication is the life blood of every organisation and its effective use helps build a proper chain of authority and improve relationships in the organisation. So the importance of developing skills in interpersonal communication is necessary.
While understanding the importance of communication, one needs to be clear regarding the difference between Individual communication and Organizational communication. Communication in the organisation takes place through individuals. However, there is a vast difference in the manner in which personal – communications and organizational – communications are carried out. There is a sequence that needs to be followed in organizational communication. It is skilled, chair bound, predetermined and continuous. To communicate well, one needs to know the frames of reference to be able to assess other people so as to pass information and build relationship.
WHAT IS COMMUNICATION ?
Communication is a process that involves transfer of information and behavioral inputs. It is the transfer of information from a sender to a receiver with the information being understood by the receiver. It is a function by which organized activity is unified. It is looked upon as a means by which social inputs are fed into social systems, a means by which behavior is modified, change is effected, information is made productive in a manner such as to achieve goals. It is absolutely essential, whether it be in a family, in a temple, in an army cantonment or in a business unit.
Communicating is a two-way process. In organisations, one communicates to get the things done, pass on and obtain information, reach decisions and achieve a joint understanding. The sender needs to formulate a message so that it is understandable to the receiver. This responsibility pertains primarily to written and oral communication and points to the necessity for planning the message, stating the underlying assumptions and applying the generally accepted rules for effective writing and speaking. The greater the integrity and consistency of written, oral and nonverbal messages, as well as of the moral behavior of the sender, the greater is the acceptance of the message by the receiver.

Communication covers a wide topic area. Any definition of a topic as broad as communication would be too general, too complex, or too fragmented to be of much use to a community leader. We can explain various aspects of communication with definitions, but they would not be unified. One way to define communication is to explain the process of communication.
Applying the term process to communication means that it is an ongoing event. In our social interaction with others, we are communicating. Communication, therefore, is the process whereby we attempt to transmit our thoughts, ideas, wishes, or emotions to others.
For our purpose, communication involves only the information, thoughts, ideas, etc. that we want to transmit to a specific audience. The definition of communication does not include observed behavior unless the observed behavior is intended to help transmit the message. For instance, there is no communication between a leader and two group members who are having a conversation on the other side of the room, even if the leader is observing their behavior. The two group members do not intend their conversation to transmit any messages to the leader. Nor is the leader intending to transmit any messages to the two members through his observation. However, the leader can use gestures to help transmit messages to a specific audience as a part of the communication process.
The goal of communication is the acceptance of the sender's message by the receiver. If the receiver understands the meaning of a message which asks for action, but fails to act, the goal of communications is not achieved. But if the receiver does respond to the message by taking the appropriate action, the goal of the communication has been achieved.

How does Communication works?There are many communication models which serve a variety of purposes. They range from single event analyses which can be used to instruct beginners, to complex models which are usually understood only by specialists in the field of communication. We have chosen the SENDER-ENCODE-MESSAGE-CHANNEL-DECODE-RECEIVER (S.M.C.R.) Model for this publication. The S.M.C.R. model is helpful for examining a single communicative event; that is, it can isolate one event out of the ongoing communication process and illustrate the actions which take place.

SenderThe sender (or source in the S.M.C.R. model) is the transmitter of the message. There are five factors which influence the sender in any communication he transmits:
Communications skills
Attitudes
Knowledge
Position in the social system
Culture
These five factors also influence the receiver as will only be summarized here.
There are five verbal communication skills which determine our ability to transmit and receive messages. Two are sending skills: speaking and writing. Two are receiving skills: listening and reading. The fifth is important to both sending and receiving: thought or reasoning. The extent of the development of these skills helps determine our ability to communicate verbally.
The effectiveness of our communications is also determined by our ability with nonverbal communications skills. A stern look of disapproval from the group leader readily communicates to the group member receiving the look that something he said or did was not well taken.
Attitudes, the second factor influencing the sender and receiver, are hard to define. For our purpose we will say that an attitude is a generalized tendency to feel one way or another about something. For instance, you may have a favorable or an unfavorable attitude toward voluntary groups working to solve community problems. If your attitude on this matter is favorable, you may, however, feel that certain problems could be better handled by the city council.
Attitudes influence our communication in three ways. Attitudes toward ourselves determine how we conduct ourselves when we transmit messages to others. If we have a favorable self-attitude, the receivers will note our self-confidence. If we have an unfavorable self-attitude, the receivers will note our uneasiness. However, if our favorable self-attitude is too strong, we tend to become brash and overbearing, and our communication loses much of its effect with the receiver.

Attitude toward subject matter affects our communication by predetermining the way we work our messages about certain subjects. An example would be a community leader with a favorable attitude toward bringing industry into the local area. He is likely to talk about only the good that industry could achieve. He may deliberately neglect to mention the difficulties encountered in trying to recruit new industry or any possible undesirable effects that might result.
Attitude toward the receiver or the receiver's attitude toward the sender is the third attitude item which influences our communication. Our messages are likely to be very different when communicating the same content to someone we like and then to someone we dislike. We also structure our messages differently when talking to someone in a higher position than ours, in the same position, or in a lower position, regardless of whether we like them or not.
Knowledge level has a bearing on our ability to communicate effectively about a subject. A businessman might feel ill at ease trying to talk with a farmer about hogs, cattle, corn, or beans. The farmer would probably not feel qualified to talk about city slums, urban traffic problems, or city government. They may both feel quite comfortable discussing politics, however.
The position of the sender and the receiver in their respective social systems also affects the nature of the communicative act. Each one of us occupies a position in one or more social systems, such as our family, work groups, church, community, or the organizations to which we belong. We perceive those with whom we communicate as occupying a similar, higher, or lower position in their respective social systems. (This ties in with the previous sections on attitudes toward the receiver or sender.)
Our culture also influences our communication effectiveness. Communication is more effective between persons with similar cultural backgrounds. Culture is relatively independent of social position in many cases. For instance, a voluntary association leader in Iowa could probably communicate better with the people in his own group, because of their similar cultural background, than he could with a leader in the same organization in the East.
Encoding the Message
Another problem with the message—the meaning—we want to send is that we can't send it directly. We can't plug their mind into our mind. To convey our message, we have to use symbols—written or spoken words, pictures, sounds, physical gestures, and movements. Yet none of these symbols are precise. They never represent a

perfect match with the thought, ideas, information, or message we hold in our mind. Although we may try for the exact word or phrase or illustration, inevitably the symbol we choose to represent our thought is less than perfect. Words are a particular problem. We must use words to communicate, but meanings for the words we use are in the people hearing or seeing them, not in the words themselves. And the same word can have so many possible meanings.

MessageThe message is what the sender attempts to transmit to his specified receivers. Every message has at least two major aspects: content and treatment.
The content of the message includes the assertions, arguments, appeals, and themes which the sender transmits to the receivers. For instance, community leaders may wish to send a message to community organizations appealing for financial support for a new swimming pool. The content of the message may include the results of a survey showing the need for a new swimming pool, the proposed plan for the new pool, the costs involved, and the appeal for financial support.
The treatment of the message is the arrangement or ordering of the content by the sender. In the above example, the community leaders can arrange the content in many ways. The receiver is likely to be more receptive to the message, however, if the sender talks about the survey illustrating the needs prior to talking about the costs and making the appeal for financial support.
The selection of content and the treatment of the message depend upon our communication skills, attitudes, knowledge level, our position in social systems, and our culture. The selection of content and the treatment of the message we use also depends upon our audience and their communication skills, knowledge, attitudes, social position, and culture. A doctor, for example, would probably select different content and treat the message differently when talking about the same subject to two different audiences, i.e., his fellow doctors and a group of community leaders.

ChannelSocial scientists recognize two types of channels: (1) sensory channels based on the five senses of sight, sound, touch, smell, and taste, and (2) institutionalized

means such as face-to-face conversation, printed materials, and the electronic media.
We use the institutionalized means to transmit most of our messages. Each institutionalized medium requires one or more of the sensory channels to carry the message from the sender to the receiver. For instance, when we use face-to-face conversation (an institutionalized medium) we make use of sight (gestures, expressions), sound (voice, other noises), and possibly touch, smell, or taste.
Social Scientists have generally found that the receiver's attention is more likely to be gained if the sender uses a combination of institutionalized means using two or more sensory channels. Suppose, for example, someone tells your group that the quality of education in your community is not as good as the public is led to believe. If your group can discuss the problems face-to-face with school administrators during visits to the school (sight and sound) as well as hear about them through institutionalized means such as television and newspapers, they are more likely to pay attention to the message.
When applying the multi-channel concept to real situations, you need to consider the three basic institutionalized means and a minimum of two of the sensory channels, specifically sight and sound.
Face-to-face conversation has the greatest potential for getting the receiver's attention. It should be the primary institutionalized means used by leaders in sending messages to their group members. However, leaders should supplement face-to-face conversation with other institutionalized means and sensory channels in their continuing effort to gain the attention of their group members.

Decoding
Before our message can have meaning to the recipient, it must be decoded. Our listener, reader, employee, customer—the person to whom we are trying to convey our meaning must interpret our words, pictures, gestures. To each, he or she adds meaning—and not necessarily the meaning we intended. Perhaps the words we choose don't mean the same to them. Perhaps we have chosen specialized symbols—jargon, pictures, illustrations they don't understand. Perhaps they filter out part of our message so they hear only what they want to hear. Perhaps, due to noise, they miss key words. We choose a formal public medium—the public announcement—for convenience. They interpret our choice as “cold” and

“insensitive.” Worse, most people are poor listeners. They become passive, go into neutral—and truly absorb by some estimates as little as 25 percent of what they hear.

ReceiversThe receiver in the S.M.C.R. model must attend to, interpret, and respond to the transmitted message. The goal of communication is reached when the receiver accepts the sender's message. Attention and comprehension are the means the receiver used to attain the goal of acceptance of the message.
Attention is the process by which the receiver tunes in on a message and listens to it, watches it, or reads it. The sender must consider his receiver and treat the message in such a way that the receiver's attention is more easily gained and retained.
Comprehension implies understanding of the message by the receiver. Here again, the sender must consider his intended receiver and use message content and treatment that will enable the receiver to understand the message.
Once the receiver has attended to the message and comprehended or understood the content, his next task is to accept the message on at least one of three levels: the cognitive, that is, the receiver accepts the message content as true; the affective, the receiver believes that the message is not only true but good; overt action, where the receiver believes the message is true, believes it is good, takes the appropriate action.
The sender can do much in deciding on his content and treatment of the message to gain the receiver's attention and comprehension. However, he has little control over the receiver's acceptance of the message. One consideration required at this point is to note that receivers are more inclined to accept message contents which agree with their previous attitudes. The sender has a less difficult task if his message agrees with the receiver's attitudes. If the receiver disagrees with the sender's message, acceptance is less likely.

FeedbackFeedback is the sender's way of determining the effectiveness of his message. During feedback the direction of the communication process is reversed. When providing feedback, the original receiver goes through the same process as did the original sender and the same factors influence him as they did the sender.
The receiver may use the same channel for feedback as the sender used for the original message; this is usually the case in face-to-face conversation. Or the receiver may take a different channel, as might be the case when you as a leader transmit a message to your group requesting action on a matter and the group acts or does not act in the way you asked. The group's actions have then become the feedback. Another example might be the increased sales of a product due to radio and television advertising. The purchase of the product by the public provides feedback to the manufacturer on the effectiveness of the communicated message.
In face-to-face conversation, feedback is more easily perceived. The sender can tell if the receivers are paying attention when he speaks to them. If a receiver falls asleep or looks at other things in the surrounding environment, the sender realizes that he does not have the receiver's attention.
If the sender sees furrowed brows or questioning facial expressions in his receivers, he knows that they did not comprehend his message. However, the overt action taken by the receiver is the feedback that the sender uses to determine the amount of influence he has had with the receiver.
Feedback measures influence. We know that democratic leadership involves influencing others. When a group has been successful in raising money for a community project, they can rightfully feel that they were influential. If the group had failed in their effort to raise the money, one of the reasons could be that they were not influential in the community. If your group takes the action you want them to take, you have been influential; if it does not, then you were not influential.
Feedback provides a method of eliminating mis-communication. It is most effective in face-to-face conversation where feedback is instantaneous. If a group leader asks one of the members for some ideas on projects for the next year and the member suggests having travel films, the leader knows immediately that mis-communication has occurred. The group member suggested program ideas and not project ideas. The feedback would be effective if the leader were to immediately clarify the difference between programs and projects. Had the situation not been face-to-face, the group member might still be thinking of travel films for next year's project.

Barriers to effective communication
Breakdowns of communication channels, is a frequent challenge that managers face. Communication problems signify more deep-rooted problems than those that appear prima facie. The barriers may exist either at the transmission stage or at the feedback stage. It may so happen that the sender is unable to properly channelise the message, or it may also be wrongly received. The important point is to understand the barriers that a manager faces at various stages so that they can be properly dealt with.
Faulty Planning
The prerequisite of effective communication is accurate planning. The message should be properly planned and then delivered. Which channel links are to be adopted needs to be planned out in advance. The contents of the message should be drawn after considering all the aspects. A poorly designed message looses all its worthiness. Besides, the purpose of the message also needs to be clearly stated. Hence, faulty planning leads to breaking up of communication lines.
Vague Presumptions
The non-communicated assumptions that underline the message are extremely dangerous. The sender presumes a certain part and accordingly forwards the message. It is not necessary that the receiver shall also presume things in the same manner. This may lead to confusion and chaos. Unclarified and vague presumptions lead to greater dangers. For example, a senior officer gives a call to the junior stating that on certain days he will be out of town assuming that the junior shall make necessary staying arrangements for him. The junior receives this message assuming that senior manager is simply informing him of his absence so that he can take over the responsibility and that all staying arrangements were already taken care of by the senior.
Semantic Distortion :
A single word conveys lots of different meanings. Each word is understood in reference to the context of the sentence as well as place and situation it is used at. Semantic Distortion can be deliberate or accidental. When it is deliberate, it is intended so but the one that is accidental hinders the progress of communication. It renders ambiguity to the message and every different individual may come to his own conclusion in the end.

Muddled messages
Effective communication starts with a clear message. Contrast these two messages: "Please be here about 7:00 tomorrow morning." "Please be here at 7:00 tomorrow morning." The one word difference makes the first message muddled and the second message clear. Muddled messages are a barrier to communication because the sender leaves the receiver unclear about the intent of the sender. Muddled messages have many causes. The sender may be confused in his or her thinking. The message may be little more than a vague idea. Feedback from the receiver is the best way for a sender to be sure that the message is clear rather than muddled. Clarifying muddled messages is the responsibility of the sender. The sender hoping the receiver will figure out the message does little to remove this barrier to communication.

Stereotyping
Stereotyping causes us to typify a person, a group, an event or a thing on oversimplified conceptions, beliefs, or opinions. Stereotyping can substitute for thinking, analysis and open mindedness to a new situation. Stereotyping is a barrier to communication when it causes people to act as if they already know the message that is coming from the sender or worse, as if no message is necessary because "everybody already knows." Both senders and listeners should continuously look for and address thinking, conclusions and actions based on stereotypes.

Wrong channel
Variation of channels helps the receiver understand the nature and importance of a message. Using a training video on cleaning practices helps new employees grasp the importance placed on herd health. A written disciplinary warning for tardiness emphasizes to the employee that the problem is serious. A birthday card to an employee's spouse is more sincere than a request to the employee to say "Happy Birthday" to the spouse. Simple rules for selection of a channel cause more problems than they solve. In choice of a channel, the sender needs to be sensitive to such things as the complexity of the message.

Language
Words are not reality. Words as the sender understands them are combined with the perceptions of those words by the receiver. Language represents only part of the whole. We fill in the rest with perceptions. Trying to understand a foreign language easily demonstrates words not being reality. Being "foreign" is not limited to the language of another country, it can be as much a barrier to communication as a foreign language.

Lack of feedback
Feedback is the mirror of communication. Feedback mirrors what the sender has sent. Feedback is the receiver sending back to the sender the message as perceived. Without feedback, communication is one-way. Feedback happens in a variety of ways. Asking a person to repeat what has been said, e.g., repeat instructions, is a very direct way of getting feedback. Feedback may be as
subtle as a stare, a puzzled look, a nod, or failure to ask any questions after complicated instructions have been given. Both sender and receiver can play an active role in using feedback to make communication truly two-way. Feedback should be helpful rather than hurtful. Prompt feedback is more effective that feedback saved up until the "right" moment. Feedback should deal in specifics rather than generalities. Approach feedback as a problem in perception rather than a problem of discovering the facts.

Poor listening skills
Listening is difficult. A typical speaker says about 125 words per minute. The typical listener can receive 400-600 words per minute. Thus, about 75 percent of listening time is free time. The free time often sidetracks the listener. The solution is to be an active rather than passive listener. One important listening skill is to be prepared to listen. Tune out thoughts about other people and other problems. Search for meaning in what the person is saying. A mental outline or summary of key thoughts can be very helpful. Avoid interrupting the speaker. Providing feedback is the most important active listening skill. Ask questions. Nod in agreement. Look the person straight in the eye. Lean forward. Be an animated listener. Focus on what the other person is saying. Repeat key points. Active listening is particularly important in dealing with an angry person. Encouraging the person to speak, i.e., to vent feelings,

is essential to establishing communication with an angry person. Repeat what the person has said. Ask questions to encourage the person to say again what he or she seemed most anxious to say in the first place. An angry person will not start listening until they have "cooled" down. Telling an angry person to "cool" down often has the opposite effect. Getting angry with an angry person only assures that there are now two people not listening to what the other is saying.

Physical distractions

Physical distractions are the physical things that get in the way of communication. Examples of such things include the telephone, a pick-up truck door, a desk, an uncomfortable meeting place, and noise. These physical distractions are common on farms. If the phone rings, the tendency is to answer it even if the caller is interrupting a very important or even delicate conversation. A supervisor may give instructions from the driver's seat of a pick-up truck. Talking through an open window and down to an employee makes the truck door a barrier. A person sitting behind a desk, especially if sitting in a large chair, talking across the desk is talking from behind a physical barrier. Two people talking facing each other without a desk or truck-door between them have a much more open and personal sense of communication. Uncomfortable meeting places may include a place on the farm that is too hot or too cold. Another example is a meeting room with uncomfortable chairs that soon cause people to want to stand even if it means cutting short the discussion. Noise is a physical distraction simply because it is hard to concentrate on a conversation if hearing is difficult.

Introdution

2008-09-01T09:46:00.000-07:00

· A computer is a machine which works from a set of pre-written instruction (Program). A computer will (under the control of its program) perform different things depending on the values of the data provided with from moment to moment. A computer program which is not built-in, but is brought into action as and when it is required.

· Application Generator - It is a program, which writes program such as Pascal, Oracle, VB and soon.

· Source program – It is human written program that is easy for a human being to read, write and understand. Example: writeln (Number), cin>Name. Object program (Binary) - It is machine understandable program, which is easy for a computer to read and act upon. Example: (Binary) 0111 0011 1001 0110.

· High Level Language – It is English like Statement Language, which is relatively easy for humans to follow. Example :- COBOL, FORTRAN, SQL, PASCAL. Low Level Language - It is Machine like Statement Language, Which is relatively easy for computers to translate and execute. But it is not natural for human beings. Example:- Machine code (binary), Mnemonic, Assembler.

· Serial Processing - One Process after another until all of the processes were completed. (Example: Program Instruction Processing). Parallel Processing - Processing where some operations run concurrently with others (Two Processes taking place in the computer at the same time. Example:-The peripheral controllers in the computer). Parallelism may exist between phases of an instruction’s execution between data transfer and processing, or between the operations of multiple independent processors.

what is programme?

· Programming language is a set of words, symbols, and codes that enables a programmer to communicate a solution algorithm to the computer. Needed to allow human begins and computer to talk to each other.

· A programmer can use a variety of programming language to code a program.

· A program development tool consists of user-friendly software products designed to assist both programmers and non-technical users with the creation of information system solution.

Generation of Programming Language.

· The first generation of language was the machine language. Machine language instruction uses a series of binary digits or a combination of numbers and letters that represents binary digits. Instructions and addressed were numerical.

· The second generation of language was the symbolic instructions or mnemonics and addresses. To convert the assembly language source program into machine language, you use an assembler. Example, IBM, BAL and VAX macro.

· The third generation language was the programmer concentration of structured programming and database management. Is a procedural language requires the program instruction tell the computer what to accomplish and how to do it. Example, FORTRAN, ADA, COBOL, Pascal, C and BASIC.

· The fourth generation (4GL) was the non-procedural type language, the programmer only specifies what the program should accomplish without explaining how. Example. SQL, Postscript, and relational database orientation.

· The fifth generation (5GL) was concerned on Artificial Intelligence and Fuzzy Logic.

Advantages and disadvantages of each generation of language.

· Readability of the language.
· Ease of writing the language.
· Reliability of the language.
· Cost of development.
· Syntax complexity.
· Language standards.

Data types and number Structures.

· Electronic Computers in the earliest days have represented everything stored and used within them (instructions, numbers, text – everything) in binary.

· Binary – a number systems to base 2, that is, with only two values, zero and one.

· Bit – Binary digit, can only have the value 0 or 1.

· Data Types:- It is a Format of Types assign to the data. The common Data Types are:-
A. Integer (Number)
B. Real (Number)
C. Character (Text)
D. Boolean (Logical)

· Integer:- Whole Numbers, This exist in several sizes ( Numbers up to 127 within seven bits, up to 32,767 within 15 bits and up to 2,147,483, 647 within 31 bits) , but the most commonly used is type int. This type requires two bytes of storage and holds numbers in the range -32,768 to 32,767). Example:- 1, 2, 30,000 and -27.

· Real :-Real number composed of a Mantissa and an Exponent. The Mantissa specifies the significant digits. The exponent is the power to which the base must be raised. Real - point data types represent numbers with a decimal place - like 3.1415927, 0.0000625, and -10.2. They have both an integer part, to the left of the decimal point, and a fractional part, to the right. Which are used for measurable quantities like distance, area, temperature, and so on, and typically have a fractional part.

· Character :- This data types made for storing letters, numbers and symbols (Alphanumeric). The letters such as:- "Abu, Ramu", Numbers value from -128 to 127 ( 1,3, 40,00, -555) and Symbols (@,%,&). This type commonly used to store ASCII characters (is a way of representing characters such as 'a', 'b', '$', '3').

· Boolean: –This is logical data, which can have the value, “True” or “False”. They can be held in one bit, and Conventionally, 1 = True and 0 = False.

· Byte – a group of 8 bits. A very common size for units of storage in computers.

· Hexadecimal – a number system to base 16. Occupies exactly 4 bits in Binary. Values are, in ascending order: 0 to 9, A, B, C, D, E, F (where A =10 & F = 15). “Carry” works exactly as in Decimal, with 16 being Hex 10; 255 being Hex FF and 256 being Hex 100.

Program Execution.

1. Production of source code

· The language used is defined for the programmer and the choice of language depends on what is appropriate for the task in hand, but also what is available within the organisation where the development is carried out.

2. Translation

· Compiler – A computer program that translates a Source Program into a semi-compiled program.

· Semi-compiled program – a program that has been partially translated from Source to Object form. It is still missing some standard routines from a library of routines. Interpreter – a computer program that translates and executes Source Programs statement by statement. Compilation, Linking and Execution are not separate.

3. Linking
o Linker – A computer program that takes a semi-compiled program and adds the required modules (standard routines) from library, to create an Object Program.

4. Running
o With the completion of linking, the program is able to execute and run at high efficiency.
o This situation is different in interpreted language, where the running happens at the same time as the translation.

· Methodology – a written-down set of rules for getting the most effective results (or to be more accurate, for avoiding the worst mistakes). It will tell you when it is a good idea to pause, make sure things are written down and get them checked so that you don’t “plough on” with some ideas or approach which will not deliver what is required.
· In the program development stage, every system’s development goes through a number of progressive stages that are in nature the development processes, which are:]

Feasibility (Can we do anything?)
Analysis (What exists? What is needed?)
Design (How will we do it)
Development (Create it; Check : a) It works, b) It does what's wanted)
Implementation (Install and use it)
Maintenance (Correct, update, extend)
Phase-Out (Replace, Decommission)

Feasibility Study
Determine the system requested is feasible. This will be determine by using four main Feasibility Studies.
Organizational Feasibility
Proposed system fits to their plans for integrating sales, marketing, and financial system.
Economic Feasibility
Savings in checkout costs.
Increased sales revenue
Increased profits
Decreased investment in inventory
Technical Feasibility
Capability, Reliability, Availability of hardware, Software and network also personnel.
Operational Feasibility
Acceptance of salespeople
Store management support
Customer acceptance

Requirement Analysis
1. This is carried out to understand what is wanted, through means of interviewing, holding meetings and reviewing existing processes (if any).
2. Once it is known what is wanted, it is then written down so that people can see what is being requested and agrees that this specifies – clearly, completely and unambiguously.
3. If the requirement analysis is not clear, complete and unambiguous, then everything else from there on is being built on very weak foundation, and is very likely to be seriously deficient

Design
1.The design should be understood by the technicians in the detail of the requirement.
2.The system specification is developed to satisfy the requirement and agreed to the developing a solution in this manner.
3.Once the system specification is agreed, the System Design is developed with details of the programs needs, the input they receive, the output they produce, the data they work with and the formulae they employ.

Example of Functional Requirements
User Interface Requirements
Easy-To-Use
Processing Requirements
Fast, Automatic Calculation
Storage Requirements
Fast retrieval and update of data
Control Requirements
Signal for data entry errors

Development
1. This is the process of developing actual system that will satisfy the functional requirements of the proposed system.
2. Here they will determine the same standard of codings
3. At the end of the session they will:-
All the coding must works
It should be bug free
It should be readable and maintainable.

A Few other Things to be checked on:
Building Modification
Equipment purchase
Power Cabling
Training Courses
Conversion Programs
Backup and Restore Programs
Installation Routines
De-Installation Routines

Testing

"Why Do We Need Testing"

1. Testing is used often as a means of determining quality and proving that software is fit for its purpose.
2. It is not just to be sure that a program meets technical requirements, but also that it is economical and maintainable.
3. A contents checklist of testing.
Contents
Testing Philosophy
File Creation
Program Suite Input
Program Suite Output
Input / Output Handling
Test Data

4. Testing is an extension of V & V procedures
Verification
Validation

Verification
Attempts to find errors by executing a program in a tested or simulated environment. This Checks that the work requirement specified at the beginning of any phase of work has been completed at the end.

Validation
Is the process of finding errors by executing a program in the real environment. This provides a global check that all the functional, safety and contractual requirements specified have been completed at the end of the project.

Implementation
1. Where the old system is stopped and new system is introduced.
2. Test the system, and train people to operate and use it.
3. Acquire hardware and software.

Maintenance
1. It is post implementation review process to monitor, evaluate and modify the system as needed.

Phase out
· This is the process of changing the system as a whole.
· The developers will create better system which is best suited to their needs and wants.

The source code is required to be translated into the object code (which the machine executes) as being a simple case of compilation or interpretation.
There are two main modes of translation of the language:
1. The Compiler
The first thing which the compiler does with your source program is to Syntax Check it - in other words, to see if it can make sense of it. It does this by applying the rules of the language - its "grammar" if you will - to make sure that none of them have been broken. In any human language, we can be very "loose" with the grammatical rules, and people will still understand what you mean. Programming languages are not like that. You must adhere precisely to the rules of grammar. Even a missing full stop in a language like COBOL can have far- reaching effects, causing errors that are difficult to identify and pin down.

Given that none of the rules have been obviously broken - and the compiler will not let you continue if they have - the compiler starts to translate the program.

Translation proper starts by working out what goes where, by building a map or index for the named areas of storage you have formally defined. This is easy in COBOL (where it is all laid out in the Data Division) and less easy in some versions of BASIC, where you do not always have to define a storage area before using it.

The compiler then scans the procedures you have written, extracting the data names that have been used. By the end of this process, in a language like COBOL, there should be no data names mentioned in the Procedure Division of the program, which have not been defined in the Data Division. If there are, the programmer has made a mistake! In a language like BASIC, however, you cannot be so certain. For this reason, even when writing programs in BASIC, it is considered good practice to define all of the data areas, so that if the compiler flags any undefined names, they are probably mistakes.

Either on the same scan of the procedures, or on separate scans (it depends on the particular compiler) two lists will be built up - one of the procedures called, and one of the procedures found. If the program uses a procedure, then that procedure must exist. Very often, it will be somewhere within the same program, but quite possibly it will be a standard routine that exists elsewhere. The compiler matches up the list of procedures needed with the list of procedures found in the program, and produces another list - of procedures it couldn't find. This is the list of "external references" which are expected to be on some library somewhere.

Finally, the compiler encodes the operations that have been specified in the written procedures - things like "ADD" or "MOVE" (from COBOL) or "=" or "^" (from BASIC) or "+" or "- " (from either).

At this point, some - but not all - of the program is in a form that could be executed. However, there are the external references to deal with. The compiler stores the work so far, and finishes.

The program is in what we call "semi-compiled" form at this juncture. It is a good idea for the programmer to check the compiler's report of the unresolved references to identify any that should not be there, correct them, and re-compile. This usually arises because a resolvable reference has been mis-typed, but perhaps a routine has been forgotten about, or was expected to be provided by someone else, yet remains "absent without leave".

The Linker
It is the linker's task to resolve all of the (intentional) external references. To do this, the linker reads the list of external references generated by the compiler, and attempts to identify matching routines on the library files to which it has access.

Once it has built a match-list, the linker reads the semi-compiled program and adds the required routines from the libraries. Then it replaces the external references by internal references (because the "missing" routines are now present). Now virtually the entire program is executable, and it is written to an output file in what we normally and slightly incorrectly call "object form".

"Slightly incorrectly" because there may still be unresolved references, and these fall into two categories. Mistakes have to be dealt with by the programmer, which involves editing the source code, re-compiling and re-linking. Other references are to routines that may be shared between all programs that use them, and are not properly part of any individual program. These external references can only be resolved when the program is about to be run - and that is done by the loader or binder.

The Loader
It is the Loader that brings our complete program into the computer to be executed. Clearly, this is the last opportunity for external references to be resolved, and these are expected to be references to routines which are already present in the computer's memory.

If the routines are not present, an attempt is made to locate them (they would normally be optional modules of the operating system) and to load them. Then the remaining external references can be resolved making the program truly executable, and it is started.

Some systems allow this "fully bound" version of the program to be stored for later use. This leads to very fast loading, but does not allow for the efficiencies if inter-program code sharing.
Summary - Compiler, Linker and Loader
The compiler checks to see if the rules of the language are applied and adhered precisely
The linker resolves all of the external references to build the routines on the library files to which it has access.
The loader brings our complete program into the computer to be executed.

2. Interpreter
Having understood the translation process for compiled languages, the translation process for interpreted languages may be explained relatively quickly. Think of "interpretation" as "statement-by-statement, on-demand compilation, linking and execution".

Actually, interpretation as characterized above - where a statement is typed in, then immediately obeyed - is more strictly called "immediate-mode interpretation". This is to distinguish it from "deferred-mode interpretation" where all the statements are typed in, and then the program is run without any (separate) compilation process.

Interpretation - whether immediate or deferred - is fundamentally an on-line process, with the user at a terminal interacting directly with a computer.

BASIC was originally conceived as an interpreted language; compiled versions being very much a deviation from the original intentions. In BASIC, in response to the "Ready" prompt, you can type:

PRINT "Hello Mum!"

and the system would immediately respond on your terminal:

Hello Mum!
Ready

This is Immediate Mode. The statement has been syntax checked, compiled, linked and executed. However, if you precede the command with a number, like this:

20 PRINT "Hello Mum!"
the system only syntax checks the statement and (if it is OK), provides you with the next line number, it does not obey the command. The program is only executed when you enter a "RUN" command. This is Deferred Mode, where

compilation, linking and execution are deferred until a RUN command is given.

Summary Interpreter
This form of translation provides a “statement-by-statement” on-demand compilation, linking and execution.

Error Messages
Error Messages can be encountered at any stage of the translation process from source to object program.
There are different types of errors.
Syntax Error
Logic Error
Runtime Error
Semantic Error
Syntax Error
This is the error due to violations of grammatical rules and format of the programming language.
It can be detected by both compilers and interpreters.
Syntax errors are also known as compilation errors.
Example
· Invalid Data names
· Undefined Variables
· Wrong Spelling of Keywords

Logic Error
o This is an error due to misunderstanding of requirements or incorrect algorithms used, resulting in an incorrect result.
o This type of error cannot be detected by both compiler and interpreter.
Example
· Area = Length + Breadth
(Which support to be "Area= Length * Breath"
Runtime Error
o This type of error can be detected only during the running of the program.
o It also cannot be detected by either compiler or interpreter.
Example
· Input / output error during execution
· Calculation of non-numeric data
· File opened but not closed during execution

Semantic Error
o This type of error occur only due to misunderstanding of a syntax of the meaning of a programming language.
o This type of error cannot be detected by both compiler and interpreter.
Example
· A = B + C * D
(The syntax of the programming language will do "C * D" first then add "B" but the programmer interprets it as "B + C" first and then add "D" later.)