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Question 1) What do you undesrtand by an Information System? Explain variouscategories of information system

Ans. Information System is a combination of people, hardware, software, communication devices,

network and data resources that processes (can be storing, retrieving, transforming information) data

and information for a specific purpose. The operation theory is just similar to any other system, which

needs inputs from user (key in instructions and commands, typing, scanning). The inputted data then

will be processed (calculating, reporting) using technology devices such as computers, and produce

output (printing reports, displaying results) that will be sent to another user or other system via a

network and a feedback method that controls the operation.

With the helps of Information System, businesses are able to process and operate its daily works more

accurate and easier. All data and information are stored in electronic database which is much safer and

easier to be attached then traditional method.

The main kinds of information systems in business are described briefly below:

Executive

Support Systems

An Executive Support System ("ESS") is designed to help senior management make

strategic decisions. It gathers, analyses and summarises the key internal and external

information used in the business.

A good way to think about an ESS is to imagine the senior management team in an

aircraft cockpit - with the instrument panel showing them the status of all the key

business activities. ESS typically involve lots of data analysis and modelling tools such

as "what-if" analysis to help strategic decision-making.

Management

Information

Systems

A management information system ("MIS") is mainly concerned with internal

sources of information. MIS usually take data from the transaction processing

systems (see below) and summarise it into a series of management reports.

MIS reports tend to be used by middle management and operational supervisors.

Decision-Support

Systems

Decision-support systems ("DSS") are specifically designed to help management make

decisions in situations where there is uncertainty about the possible outcomes of

those decisions. DSS comprise tools and techniques to help gather relevant

information and analyse the options and alternatives. DSS often involves use of

complex spreadsheet and databases to create "what-if" models.

Knowledge

Management

Systems

Knowledge Management Systems ("KMS") exist to help businesses create and share

information. These are typically used in a business where employees create new

knowledge and expertise - which can then be shared by other people in the

organisation to create further commercial opportunities. Good examples include

firms of lawyers, accountants and management consultants.

KMS are built around systems which allow efficient categorisation and distribution ofknowledge. For example, the knowledge itself might be contained in word processing

documents, spreadsheets, PowerPoint presentations. internet pages or whatever. To

share the knowledge, a KMS would use group collaboration systems such as an

intranet.

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Transaction

Processing

Systems

As the name implies, Transaction Processing Systems ("TPS") are designed to process

routine transactions efficiently and accurately. A business will have several

(sometimes many) TPS; for example:

- Billing systems to send invoices to customers

- Systems to calculate the weekly and monthly payroll and tax payments- Production and purchasing systems to calculate raw material requirements

- Stock control systems to process all movements into, within and out of the business

Office

Automation

Systems

Office Automation Systems are systems that try to improve the productivity of

employees who need to process data and information. Perhaps the best example is

the wide range of software systems that exist to improve the productivity of

employees working in an office (e.g. Microsoft Office XP) or systems that allow

employees to work from home or whilst on the move.

Ques2.Show with reference to a block diagram, the structure of a digital computerand the interconnection of various

units. Explain the functions of various unitsbriefly

Block Diagram of Computer :

A computer can process data, pictures, sound and graphics. They can solve highly complicated problemsquickly and accurately.

Input Unit:

Computers need to receive data and instruction in order to solve any problem. Therefore we need to

input the data and instructions into the computers. The input unit consists of one or more input devices.

Keyboard is the one of the most commonly used input device. Other commonly used input devices are

the mouse, floppy disk drive, magnetic tape, etc. All the input devices perform the following functions.

Accept the data and instructions from the outside world.

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Convert it to a form that the computer can understand.

Supply the converted data to the computer system for further processing.

Storage Unit:

The storage unit of the computer holds data and instructions that are entered through the input unit,

before they are processed. It preserves the intermediate and final results before these are sent to the

output devices. It also saves the data for the later use. The various storage devices of a computer system

are divided into two categories.

1. Primary Storage: Stores and provides very fast. This memory is generally used to hold the program

being currently executed in the computer, the data being received from the input unit, the intermediate

and final results of the program. The primary memory is temporary in nature. The data is lost, when the

computer is switched off. In order to store the data permanently, the data has to be transferred to the

secondary memory.

The cost of the primary storage is more compared to the secondary storage. Therefore most computers

have limited primary storage capacity.

2. Secondary Storage: Secondary storage is used like an archive. It stores several programs, documents,

data bases etc. The programs that you run on the computer are first transferred to the primary memory

before it is actually run. Whenever the results are saved, again they get stored in the secondary

memory. The secondary memory is slower and cheaper than the primary memory. Some of thecommonly used secondary memory devices are Hard disk, CD, etc.,

Memory Size:

All digital computers use the binary system, i.e. 0s and 1s. Each character or a number is represented

by an 8 bit code.

The set of 8 bits is called a byte.

A character occupies 1 byte space.

A numeric occupies 2 byte space.

Byte is the space occupied in the memory.

The size of the primary storage is specified in KB (Kilobytes) or MB (Megabyte). One KB is equal to 1024

bytes and one MB is equal to 1000KB. The size of the primary storage in a typical PC usually starts at

16MB. PCs having 32 MB, 48MB, 128 MB, 256MB memory are quite common.Output Unit:

The output unit of a computer provides the information and results of a computation to outside world.

Printers, Visual Display Unit (VDU) are the commonly used output devices. Other commonly used output

devices are floppy disk drive, hard disk drive, and magnetic tape drive.

Arithmetic Logical Unit:

All calculations are performed in the Arithmetic Logic Unit (ALU) of the computer. It also does

comparison and takes decision. The ALU can perform basic operations such as addition, subtraction,

multiplication, division, etc and does logic operations viz, >,

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It performs all calculations.

It takes all decisions.

It controls all units of the computer.

Ques3 What do you understand by a database management system? Explain theadvantages of database

management system over conventional file orienteddata processing syatem..

Ans: A database management system is the system in which related data is stored in an efficient and

compact manner. "Efficient" means that the data which is stored in the DBMS can be accessed quickly

and "compact" means that the data takes up very little space in the computer's memory. The phrase

"related data" is means that the data stored pertains to a particular topic.

Specialized databases have existed for scientific, imaging, document storage and like uses. Functionality

drawn from such applications has begun appearing in mainstream DBMS's as well. However, the main

focus, at least when aimed at the commercial data processing market, is still on descriptive attributes on

repetitive record structures.

Thus, the DBMSs of today roll together frequently needed services or features of attribute management.

By externalizing such functionality to the DBMS, applications effectively share code with each other and

are relieved of much internal complexity. Features commonly offered by database management systems

include:

Query ability

Querying is the process of requesting attribute information from various perspectives and

combinations of factors. Example: "How many 2-door cars in Texas are green?" A database

query language and report writer allow users to interactively interrogate the database, analyzeits data and update it according to the users privileges on data.

Backup and replication

Copies of attributes need to be made regularly in case primary disks or other equipment fails. A

periodic copy of attributes may also be created for a distant organization that cannot readily

access the original. DBMS usually provide utilities to facilitate the process of extracting and

disseminating attribute sets. When data is replicated between database servers, so that the

information remains consistent throughout the database system and users cannot tell or even

know which server in the DBMS they are using, the system is said to exhibit replication

transparency.

Rule enforcement

Often one wants to apply rules to attributes so that the attributes are clean and reliable. For

example, we may have a rule that says each car can have only one engine associated with it

(identified by Engine Number). If somebody tries to associate a second engine with a given car,

we want the DBMS to deny such a request and display an error message. However, with

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changes in the model specification such as, in this example, hybrid gas-electric cars, rules may

need to change. Ideally such rules should be able to be added and removed as needed without

significant data layout redesign.

Security

For security reasons, it is desirable to limit who can see or change specific attributes or groups

of attributes. This may be managed directly on an individual basis, or by the assignment of

individuals and privileges to groups, or (in the most elaborate models) through the assignment

of individuals and groups to roles which are then granted entitlements.

Computation

Common computations requested on attributes are counting, summing, averaging, sorting,

grouping, cross-referencing, and so on. Rather than have each computer application implement

these from scratch, they can rely on the DBMS to supply such calculations.

Change and access logging

This describes who accessed which attributes, what was changed, and when it was changed.

Logging services allow this by keeping a record of access occurrences and changes.

Automated optimization

For frequently occurring usage patterns or requests, some DBMS can adjust themselves to

improve the speed of those interactions. In some cases the DBMS will merely provide tools to

monitor performance, allowing a human expert to make the necessary adjustments after

reviewing the statistics collected.

A true DBMS offers several advantages over file processing.

The principal advantages of a DBMS are the followings:

Flexibility: Because programs and data are independent, programs do not have to be modified when

types of unrelated data are added to or deleted from the database, or when physical storage changes.

Fast response to information requests: Because data are integrated into a single database, complex

requests can be handled much more rapidly then if the data were located in separate, non-integrated

files. In many businesses, faster response means better customer service.

Multiple access: Database software allows data to be accessed in a variety of ways (such as through

various key fields) and often, by using several programming languages (both 3GL and nonprocedural 4GL

programs).

Lower user training costs: Users often find it easier to learn suchsystems and training costs may be

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reduced. Also, the total time taken to process requests may be shorter, which would

increase userproductivity.

Less storage: Theoretically, all occurrences ofdata items need be stored only once, thereby

eliminating the storage of redundant data. System developers and database designers often use data

normalization to minimize data redundancy.

Question 4) Explain the various file-accessing techniques in data management system.Also state the advantages and

limitations of each technique.

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Quest 5 .What is meant by Local Area Network and Wide Area Network?Differentiate between them and give one

example of each.

Ans. LANA local area network (LAN) is a group of computers and associated devices that share a common

communications line or wireless link. Typically, connected devices share the resources of a single

processor or server within a small geographic area (for example, within an office building). Usually, the

server has applications and data storage that are shared in common by multiple computer users. A local

area network may serve as few as two or three users (for example, in a home network) or as many as

thousands of users (for example, in an FDDI network).

Most LANs connect workstations and personal computers. Each node(individual computer ) in a LAN has

its own CPU with which it executesprograms, but it also is able to accessdata and devices anywhere on

the LAN. This means that many users can share expensive devices, such aslaser printers, as well as data.

Users can also use the LAN to communicate with each other, by sending e-mail or engaging

in chat sessions.

There are many different types of LANs Ethernets being the most common forPCs. Most Apple

Macintosh networks are based on Apple'sAppleTalk network system, which is built into Macintosh

computers.

The following characteristics differentiate one LAN from another: topology: The geometric arrangement of devices on the network

y busy ringy stary treey mesh

Major local area network technologies are:

Ethernet

Token Ring

LANs are capable of transmitting data at very fast rates, much faster than data can be transmitted over a

telephone line; but the distances are limited, and there is also a limit on the number of computers that

can be attached to a single LAN.

WAN:The wide area network, often referred to as a WAN, is a communications network that makes use

of existing technology to connect local computer networks into a larger working network that may cover

both national and international locations. This is in contrast to both the local area network and the

metropolitan area network, which provides communication within a restricted geographic area. Here is

how the wide area network functions, and why it is so important to communications today.

The concept of linking one computer network with another is often desirable, especially for businesses

that operate a number of facilities. Beginning with the local area network and going up to the wide area

network, this is most easily accomplished by using existing telephonytechnology. Essentially, fiber optics

are used to create the link between networks located in different facilities.

WAN Topologies

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Peer-to-Peer, Ring, Star, Mesh, Tiered

Most WANs (like the Internet) are not owned by any one organization but rather exist under collective

or distributed ownership and management. WANs tend to use technology like ATM, Frame

Relay and X.25 for connectivity over the longer distances.

Differences:

LAN

1) LAN (Local Area Network) is a computer network covering a small geographic area, like a home,office, or group of buildings

Network in an organisation can be a LAN

2) Typically owned, controlled, and managed by a single person or organization3) LANs have a high data transfer rate4) Have a small geographical range and do not need any leased telecommunication lines5) LAN can be connected to other LANs over any distance via telephone lines and radio waves6) Computers in a LAN can share a printer, if they are all in the same LAN.7) Less costly8) A LAN uses the Ethernet standard

WAN

1) WAN (Wide Area Network) is a computer network that covers a broad area (i.e., any networkwhose communications links cross metropolitan, regional, or national boundaries

Internet is the best example of a WAN

2) WANs (like the Internet) are not owned by any one organization but rather exist under collectiveor distributed ownership and management

WANs tend to use technology like ATM, Frame Relay and X.25 for connectivity over the longer distances

3) WANs have a lower data transfer rate as compared to LANs4) Have a large geographical range generally spreading across boundaries and need leased

telecommunication lines

5) Computers connected to a wide-area network are often connected through public networks,such as the telephone system. They can also be connected through leased lines or satellites

6) a WAN cannot share a printer7) A WAN is more expensive than a LAN.8) WAN uses the T1 standard

Assignment B

Quest 3 What do you understand by electronic data interchange? What is thepurpose of EDI? State its advantages over

traditional paper-based documenttransfer syatem.T

Electronic data interchange (EDI) is the electronic movement of data between or within organizations in astructured, computer-retrievable data format that permits information to be transferred from a computer program

in one location to a computer program in another location without rekeying. EDI includes the direct transmission ofdata between locations; transmission using an intermediary such as a communication network; and the exchangeof computer tapes, disks, or other digital storage devices. In many cases, content-related error checking and somedegree of processing of the information are also involved. EDI differs from electronic mail in that an actualtransaction is transmitted electronically, rather than a simple message consisting primarily of text.

EDI is used for electronic funds transfer (EFT) between financial institutions, which facilitates such commontransactions as the direct deposit of payroll checks by employers, the direct debit of consumer accounts tomake mortgage or utility payments, and the electronic payment of federal taxes by businesses. Another commonapplication of EDI involves the direct exchange of standard business transaction documentssuch as purchase

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orders, invoices, and bills of ladingfrom one business to another via computer. EDI is also used by retailbusinesses as part of their electronic scanning and point-of-sale (POS) inventory replenishment systems. Overall,EDI offers a number of benefits to businesses andthanks to the rapid evolution of the related technologyisbecoming more readily available to small businesses all the time.

Benefits of Edi over paper

EDI saves money and time because transactions can be transmitted from one information system to

another through a telecommunications network, eliminating the printing and handling of paper at one

end and the inputting of data at the other," Kenneth C. Laudon and Jane Price Laudon wrote in their

book Management Information Systems: A Contemporary Perspective. "EDI may also provide strategic

benefits by helping a firm 'lock in' customers, making it easier for customers or distributors to order

from them rather than from competitors." EDI was developed to solve the problems inherent in paper-

based transaction processing and in other forms of electronic communication. In solving these

problems, EDI is a tool that enables organizations to reengineer information flows and business

processes. It directly addresses several problems long associated with paper-based transaction systems:

y Time delaysPaper documents may take days to transport from one location to another, whilemanual processing methodologies necessitate steps like keying and filing that are renderedunnecessary through EDI.

y Labor costsIn non-EDI systems, manual processing is required for data keying, documentstorage and retrieval, sorting, matching, reconciling, envelope stuffing, stamping, signing, etc.

While automated equipment can help with some of these processes, most managers will agree

that labor costs for document processing represent a significant proportion of their overhead. In

general, labor-based processes are much more expensive in the long term EDI alternatives.

y AccuracyEDI systems are more accurate than their manual processing counterparts becausethere are fewer points at which errors can be introduced into the system.

y Information AccessEDI systems permit myriad users access to a vast amount of detailedtransaction data in a timely fashion. In a non-EDI environment, in which information is held in

offices and file cabinets, such dissemination of information is possible only with great effort, andit cannot hope to match an EDI system's timeliness. Because EDI data is already in computer-

retrievable form, it is subject to automated processing and analysis. It also requires far less

storage space.