management information system

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Strategic Role of Information System 2.1 Introduction Organizations need different types of information to support the work activities and decision making for various and organizational levels. To generate the information needed organizations use different information systems. Information system is becoming the foundation as well as necessity for many firms. The major reason for organizations to pursue information system is because the global economy has shifted from being a manufacturing, product based economy to service economy. All types of business, both large and small are using information systems, networking and internet technology to conduct their business electronically. Evidently, this has helped firms achieve new levels of efficiency, competitiveness and profitability. Strategic Advantages of Using Information System 1 It provides the information necessary to manage an organization effectively. 2. It improves organizational performance and produce profit. 3. It facilitates problem solving. 4. It leads to employee productivity. 5. It creates value for the organization by increasing the firm's Return on Investment (ROI), increasing the market value of the firm's stock and changes the quality of decision taken by the management. Types of Decisions Made In an Organization Structured Decisions: Those decisions which can be predicted in advance are structured decisions Semi-structured decisions: Those decisions which can be predicted in advance but all the variables influencing the decision cannot be considered. E.g. it Page 1

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Page 1: Management Information System

Strategic Role of Information System

2.1 Introduction

Organizations need different types of information to support the work activities and decision making for various and organizational levels. To generate the information needed organizations use different information systems.

Information system is becoming the foundation as well as necessity for many firms. The major reason for organizations to pursue information system is because the global economy has shifted from being a manufacturing, product based economy to service economy. All types of business, both large and small are using information systems, networking and internet technology to conduct their business electronically. Evidently, this has helped firms achieve new levels of efficiency, competitiveness and profitability.

Strategic Advantages of Using Information System1 It provides the information necessary to manage an organization effectively.2. It improves organizational performance and produce profit.3. It facilitates problem solving.4. It leads to employee productivity.5. It creates value for the organization by increasing the firm's Return on Investment (ROI), increasing the market value of the firm's stock and changes the quality of decision taken by the management.

Types of Decisions Made In an Organization

Structured Decisions: Those decisions which can be predicted in advance are structured decisionsSemi-structured decisions: Those decisions which can be predicted in advance but all the variables influencing the decision cannot be considered. E.g. it is predictable that the share prices will go up but the most essential variable which contributes to the price rise is unknown.Unstructured Decisions:Those decisions which cannot be predicted in advance are unstructured decisions.

2.2 Information System Classification

All information systems can be described as organization's challenges posed by the environment that will help create value for the firm. On the information needed for various levels, the following information systems are made:

Fig 2.1: Information System Classification

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2.2.1 Operational Level SystemOperational level systems support operational managers by keeping track of the elementary activities and transactions of the organization, such as cash deposit, cash withdrawal, balance transfer etc. Operational level is primary source of data for other systems and includes much minute, specific information. In this level task, resources and goals are predefined and highly structured.

2.2.1.1 Transactional Processing System (TPS)TPS is a typical operational level system. TPS are the basic business system that serves the operational level of the organization. A TPS is a computerized system that performs and records the daily routine transactions necessary to conduct business. TPS produces major information for other types of system. Managers need to monitor the status of internal operations and the firm's relation with the external environment.

TPS produces output in the form of detailed reports, lists and summaries by processing the input by sorting, listing, updating and merging etc.

STEPS IN TPS1. Data Entry: Data relating to the transactions are taken as input by the system.2. Data Validation: TPS checks the validity of the data and makes sure that they are

within the parameters set in the system. 3. Data Processing and Revalidation: The valid data taken as input are processed by

the system. While processing the data, the TPS also revalidates them with the fields in the storage

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Strategic level (DSS, ESS)

Senior manager

Middle manager

Knowledge workers

Operational manager

Mgmt level (MIS)

Knowledge level (KWS)

Operational level(TPS)

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4. Data Storage: Data after being processed are stored systematically so that they can be extracted whenever required.

5. Output Generation: TPS generates output which may be in the form of reports, list, tables etc. Generally, these reports are elaborate and present the operational level transactions. However, the reports prepared by TPS are fundamental source for other systems.

6. Query Support: Query is the request send by the user to the database to get some specific information. The query enables the user to get the required information that has been stored in the database.

2.2.2 Knowledge Level System (KLS):Knowledge level system supports the organization’s knowledge and data workers like system analysts, IT professionals who design new products and services and create new knowledge. The system used within the level is knowledge work system.

Knowledge Work Systems (KWS)KWS uses the information obtained from TPS and generally through modeling and presents them in the form of graphic models.

2.2.3 Management Information System (MIS)Management information system is the information system at the management level of an organization that serves the functions of planning, controlling and decision making by providing routine summary and exception reports.Generally, MIS serves the information need of middle level managers of an organization by providing reports. MIS serves managers interested only in weekly, monthly and yearly results, not the day to day activities.MIS takes in high volume transaction data and simple models from TPS as input and process them using simple routines such as summaries and comparisons as opposed to sophisticated mathematical tools and compress their findings in the form of pre-specified long reports to support the business decision making requirements in regular schedules.MIS is usually inflexible and is not concerned with external environment.

2.2.4 Decision Support System (DSS)Decision support system is the information system at the organization’s management level that combines data and sophisticated analytical models (tools) or data analysis tools to support semi-structured and unstructured decision making. DSS assists high level managers in making tactical and sometimes long-term strategic decisions by providing processed information. DSS help managers make decisions that are unique, rapidly changing and not easily specified in advance. DSS use both internal sources like TPS, MIS and external sources like competitor’s interest rates, share price etc. in processing information.

DSS are built explicitly with a variety of models to analyze data, or they can compress large volume of data which can be analyzed by decision makers. DSS are designed in such ways that users can work with them directly because they include user friendly, graphic oriented and

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interactive software. The user of DSS can change assumptions, ask new questions and include new data. The user can control the input or output of the system e.g. setting different values for the variables to predict the trends. It is not necessary for the user to understand complex programming or computing. DSS operates on powerful desktop personal computer, providing a system of menus that make it easy for users to enter data or obtain information.

Fig 2.2: A Sample DSS Processing

2.2.5 Executive Support SystemESS is the information system at the organization’s strategic level designed to address unstructured decision making through advanced graphics and communications.

ESS serves the senior manager of strategic level. The decisions made by them are highly non-routine because there is no agreed on procedure for arriving to a solution. ESS takes highly critical data from internal sources along with skimmed information from internal sources like MIS and DSS and filter, compress them to produce information useful for high level executives.

Revenue File

Administration Cost File

Inventory file

Liabilities File

Analytical Model Database

PCGraphic Report

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The emphasis of ESS is reducing the time and effort of executives to obtain information. ESS employs the most advanced graphics software and can deliver graphs and data from many sources immediately to the senior officer’s office or to a boardroom. However, unlike other types of information systems, ESS is not designed primarily to solve specific problems. Instead, ESS provides a generalized computing and telecommunication capacity that can be applied in solving array of problems. ESS answers questions like what business should we are doing? What are the competitors doing? Etc.

There is less use of analytical tools (as compared to DSS) in ESS. It is not necessary for user to be an expert in computer-based information system to be able to use them

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NETWORKING

3.1 Concept of Networking

In information technology, a network is a series of points or nodes interconnected by communication paths. Networks can interconnect with other networks and contain sub networks.

The most common topology or general configurations of networks include the bus, star, Token Ring, and mesh topologies. Networks can also be characterized in terms of spatial distance as local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs).

Alternatively we can define networking: If two or more than two computers are connected to each other to let the user share the resources.

Resources might be:-

Hardware resources:- Printer, Scanner, Hard disk etc Software resources: - office packages, pumori, sql, etc.

3.2 Concept Of Topology

Topology refers to the shape of a network, or the network’s layout. How the different nodes in a network are connected to each other and how they communicate are determined by the network’s topology. Topologies are either physical or logical.

Network topology is the study of the arrangement or mapping of the elements (links, nodes, etc.) of a network, especially the physical (real) and logical (virtual) interconnections between nodes. A local area network (LAN) is one example of a network that exhibits both a physical topology and a logical topology.

Any particular network topology is determined only by the graphical mapping of the configuration of physical and/or logical connections between nodes. LAN Network Topology is technically a part of graph theory. Distances between nodes, physical interconnections, transmission rates, and/or signal types may differ in two networks and yet their topologies may be identical.

3.2.1 Star Topology

All the devices are connected to a central hub. Nodes communicate across the network by passing data through the hub.

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Fig:3.1: Topology

Fig. 3.1: Topologies

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Fig 3.1 Star topology

Advantages: Easy to install Inexpensive Easy to troubleshoot Easy to reconfiguration

Disadvantages: Data transmission is low No dejure standard Lots of cable

3.2.2 Mesh Topology

Devices are connected with many redundant interconnections between network nodes. In a true mesh topology every nodes has a connection to every other node in the network.

Fig 3.2 Mesh topology

Advantages: Great reliability

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Disadvantages: Not used in practical life.

Partially connected

3.2.3 Bus Topology

All the devices are connected to a central cable, called the bus or backbone. In it, the stations are connected to the medium, which can be run in any convent shape.

Fig 3.3 Bus topology

Advantages: Easy to install Doesn’t use much cable Individual computer may fail

without affecting to others.

Disadvantages: If the main cable break down overall

network will be down Hard to troubleshoot Hard to reconfiguration

3.2.4 Ring Topology

All the devices are connected to one another in the shape of a closed loop, so that each device is connected directly to two other devices, one on either side of it.

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Fig 3.4 Ring topology

Advantages: No loss in signal quality Easy to install Easy to troubleshoot

Disadvantages: If main ring is damaged or collapsed

overall layout is damaged Hard to reconfigure Uses more cable than the bus

topology

3.3 Centralized Versus Distributed Processing

In centralized processing all processing is accomplished by one large central computer. In centralized processing all the processing load is on a single computer. On the other hand, the use of multiple computers linked by a communication network for processing is called distributed processing. In distributed processing, the processing task is distributed among personal computers, midrange computers, and mainframes linked together. One widely used form of distributed processing is client-server computing which splits processing between clients and server. Both are in network, but each machine is assigned functions it is best suited to perform.

3.4 Communication Media

Most telecommunication systems consist, in part, of some combination of input, output, processing and storage devices that are linked together through some sort of communications media. Some of the most essential telecommunication technologies and concepts are described in the following sections.

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3.4.1 Types of Media

There is variety of media link devices in a communications network. The communications channels that these provide can carry either analog or digital signals. All communications media fall into one of the two broad classes; physical lines or wireless media. These media are as follows.

a. Physical Lines:The three principal types of physical lines that dominate today’s telecommunication systems are twisted-wire pairs, coaxial cable, and fiber optic cable. While both twisted-wire pairs, coaxial cable are still commonly used, fiber optic cable is the wave of the future.

Twisted- wire pairsTwisted- wire pairs are the least expensive type of communications medium. For years, they have been used by the telephone companies to develop telephone networks. Small wires are twisted together in pairs, each of which can handle a single phone conversation, and the pairs are bound together into large bundles. Twisted-wire pairs were developed primarily as a voice-oriented, telephone communications medium; their capacity is typically lower than others cables. However LAN developers seek the twisted-wire pair’s connections because of easier connections and specific place.

Fig 3.5 Twisted pair cable

Coaxial cable (coax)Coaxial cable (coax) is primarily a phenomenon of the cable TV industry. Its development was largely motivated by the desire to bring interference-free TV to rural areas. Coaxial cable comes in all sizes and characteristics, some of which can support impressive data transmission speeds and capacities. Coax is widely used to establish LAN.

Fig 3.6 Co-axial cable

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Fiber optic cable

It is relatively new among the media technologies, consists of thousands of hair-thin strands of glass that are bound together as a cable. Data are sent along the cable as light, from a high powered, laser beam source. Compared to coaxial cable, fiber optic cable has greater channels capacity and is lighter, faster and compacter. Transmission speeds in excess of 5 gb (5 billion bits) per second are reported. Such rates would make it possible to transmit the entire contents of 30-volume encyclopedia from coast-to-coast in less than a second.

Fig 3.7 Optical Fiber

3.4.1.2 Wireless Media

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Telecommunications that do not involve physical wires are becoming more widely used. This category includes microwaves transmission ( both terrestrial and satellite), cellular radio, and wireless local area networks based on radio waves.

Broadcast RadioBroadcast radio is a wireless or unguided transmission media that distributes radio signals through air over long distances. For a radio transmission, we need a transmitter to send the broadcast radio signal and a receiver to accept it. To receive the radio signal, an antenna is placed in the range of the signal. There is a device which can be used as transmitter and receiver as well which is known as transceiver. AM and FM radio uses broadcast radio for transmitting signals of various frequency. Broadcast radio can also be used to support mobile communication network.

Bluetooth:Another wireless transmission media is Bluetooth. We are familiar with this media as it is available in our cell phones. Generally, Bluetooth is used for short range communication i.e. upto 100 meters. To use Bluetooth technology, each device must include transceiver chip and it should be within specified range.

Microwaves Microwaves are radio waves that provide high-speed signal transmission. Microwave transmission involves sending signals from one microwave station to another. A microwave station is an earth-based reflective dish that contains the antenna, transceivers and other important device necessary for microwave communications. Microwaves are limited to line-of-sight transmission, which means that microwave must be transmitted in a straight line without any obstructions in between. It is mainly used for short distance transmission. Repeaters are used at regular intervals of about 25 to 30 km between transmitting and receiving station. Data transmission rate is about 16 Gbps.

Communication SatelliteA communication satellite is a space station that receives microwave signals from an earth-based station, amplifies the signals and broadcasts the signal back over wide area to any number of earth-based station. It is much like the microwave transmission but one of its stations is a satellite orbiting the earth. The principle is the same as the microwave system, with a satellite acting as a supertall antenna and repeater. Satellite communication can provide transmission capability to and from any location on earth. The satellites are basically positioned 36000 km above equator with an orbit speed that exactly matches the earth's rotation speed. The process of transferring data to satellite is called uplink and the process of obtaining data from the satellite is called downlink.

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InfraredInfrared (IR) is a wireless transmission media that sends signals using infrared light waves. Like microwaves, infrared transmission requires a line-of-sight transmission. Many computer devices like mouse, printers etc have an IrDA port that enables the transfer of data from one device to another using infrared light waves. Generally, IR is used for very short distance data transmission.

3.5 Networking Devices

These are the hardware used in the network. These devices helps to create and manage signal flow to and from the computer. Some common network devices are:

Network Interference Card (NIC):A network interference card is an expansion card used in a computer, enabling the device to connect to a network. It co-ordinates the transmission and reception of the data, instruction and information to and from the devices or computers containing NIC card. NIC card also provides attachment point to connect a specific type of transmission media. A NIC card is designed to work with a particular type of protocol, such as Ethernet or token ring.

Fig 3.8 NIC Card

HubA network hub is a fairly unsophisticated broadcast device. Hubs do not manage any of the traffic that comes through them, and any packet entering any port is broadcast out on all other ports. Since every packet is being sent out through all other ports, packet collisions result—which greatly impedes the smooth flow of traffic

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Fig 3.9 Hub

.

SwitchA network switch, commonly referred to as just a switch, is a network device that is used to connect segments of a LAN (local area network) or multiple LANs and to filter and forward packets among them. Switches have an appearance similar to hubs (because both are box-like devices that contain a number of RJ-45 jacks), but they are actually multi-port bridges.

Fig 3.10 Switch

RouterA router is a device that connects multiple networks –including those with different protocols. A router is an intelligent communicating device that sends or routes communication traffic to appropriate work using fastest available path.

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Fig 3.11 Router

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Chapter-Four

Software Development Life Cycle (SDLC)

4.1 Introduction

4.1.1 Overview

Structured analysis uses a technique called the systems development life cycle (SDLC) to plan and manage the systems development process. Although it is primary identified with the structured analysis, the SDLC describes activities and functions that systems developers typically perform, regardless of how those activities and functions fit into a particular methodology.

Fig: 4.1 System Development Life Cycle

Review NO

The SDLC Model includes the following steps:

- Systems planning- Systems analysis- Systems design- Systems implementation- Systems operation and support (Maintenance)

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System

Planning

System

Analysis

System

Analysis

System

Implem

ent

Stop

Successf

ul

System

operation and

support

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Traditionally, the SDLC is pictured as a waterfall model, where the result of phase, often called an end product or deliverable, flows down into the next phase. In reality, the systems development process is dynamic, and constant change is common.

4.1.2 Systems Planning

Systems planning usually begin with a formal request request to the IT department, called a systems request that describes problems or desired changes in an information system. In many companies today, IT systems planning is an integral part of overall business planning.

The purpose of the planning phase is to identify clearly the nature and scope of the business opportunity or problem by performing a preliminary investigation, often called a feasibility study. The preliminary investigation is a critical step because the outcome will affect the entire development process.

4.1.3 Systems Analysis

The purpose of the systems analysis phase is to understand business requirements and build a logical model of the new system. The first step is requirements modeling, where you define and describe business processes. Requirements modeling continue the investigation that began during systems planning and involves various fact-finding techniques, such as interviews, surveys, observation, and sampling.

During the next tasks, data modeling, process modeling and object modeling, you develop a logical model of business processes the system must support. The model consists of various types of diagrams depending on the methodology being used.

The end product for the systems analysis phase is the systems requirements document. The system requirements product describes management and user requirements, alternative plans and costs and your recommendation.

4.1.4 Systems Design

The purpose of systems design is to create a blueprint for the new system that will satisfy all documented requirement, whether the system is being developed in-house or package. During systems design, you identify all necessary outputs, inputs, interfaces, and processes. In addition you design internal and external controls, including computer-based and manual features to guarantee that the system will be reliable, accurate, maintainable and secure.

4.1.5 System Implementation

During systems implementation, the new system is constructed. Whether the developers used structured analysis or 0-0 methods, the procedure is the same – programs are written, tested and documented, and the system is installed. If the system was purchased as a package, systems analysts perform any necessary modifications and configurations.

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The objective of the implementation phase is to deliver a completely functioning and documented information system.

4.1.6 Systems Operation and Support

During systems operation and support, the IT staff maintains and enhances the system. Maintenance changes correct errors and adapt to changes in the environment, such as new tax rates. Enhancements provide new featured and benefits. The objective during this phase is to maximize return on the IT investment. A well designed system will be reliable, maintainable, and scalable. A scalable design can expand to meet new business requirements and volumes.

Information systems development is always a work in progress. Business processes change rapidly, and most information systems need to be replaced or significantly updated after several years of operation.

4.1.7 Limitations of SDLC

- Structured methods are no more applicable, because things done today are fast, cheap and reality checking.

- Step by step approach of the SDLC does not suit the PC – based systems.- SDLC assumes that system requirements can be frozen during the system analysis phase.

However in the dynamic real world, user requirements change frequently.- The SDLC works better in stable environments, whereas the world information system

today is turmoil. The number and complexity of operating systems, user interfaces, network choices, software languagaes, and development tools have grown manifold.

4.2 Methodologies or models

There are several methodologies or models that can be used to guide the software development lifecycle. Some of these include:

the linear or waterfall model (which was the original SDLC method); the prototyping model;

The spiral model;

rapid application development (RAD);

joint application development (JAD);

4.2.1 The waterfall model

The waterfall model derives its name due to the cascading effect from one phase to the other as mentioned in figure. In this model each phase well defined starting and ending point, with

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identifiable deliveries to the next phase. This model is sometimes referred to as the linear sequential model or the software life cycle as shown in figure 4.2.

The model consist of six distinct stages, namely: 

1.      In the requirements analysis phase the problem is specified along with the desired service objectives (goals) and   the constraints to them are identified

  2.      In the specification phase the system specification is produced from the detailed

definitions of requirement analysis above. This document should clearly define the product function.

3.      In the system and software design phase, the system specifications are translated into a software representation. The software engineer at this stage is concerned with:

        Data structure        Software architecture        Algorithmic detail and        Interface representations

  The hardware requirements are also determined at this stage along with a picture of the overall system architecture. By the end of this stage the software engineer should be able to identify the relationship between the hardware, software and the associated interfaces. Any faults in the specification should ideally not be passed ‘downstream’. 

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Fig: 4.2 Waterfall Model

4.      In the implementation and testing phase stage the designs are translated into the software domain        Detailed documentation from the design phase can significantly reduce the coding

effort.       Testing at this stage focuses on making sure that any errors are identified and that the

software meets its required specification.5.      In the integration and system testing phase all the program units are integrated and tested to ensure that the complete system meets the software requirements. After this stage the software is delivered to the customer [Deliverable – The software product is delivered to the client for acceptance testing.]6.      The maintenance phase is usually the longest stage of the software. In this phase the

software is updated to:         Meet the changing customer needs        Adapted to accommodate changes in the external environment        Correct errors and oversights previously undetected in the testing phases        Enhancing the efficiency of the software

 Observe that feed back loops allow for corrections to be incorporated into the model. For example a problem/update in the design phase requires a ‘revisit’ to the specifications phase. When changes are made at any phase, the relevant documentation should be updated to reflect that change.

Advantages         Testing is inherent to every phase of the waterfall model

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        It is an enforced disciplined approach        It is documentation driven, that is, documentation is produced at every stage

 Disadvantages The waterfall model is the oldest and the most widely used paradigm.However, many projects rarely follow its sequential flow. This is due to the inherent problems associated with its rigid format. Namely:

        It only incorporates iteration indirectly, thus changes may cause considerable confusion as the project progresses. 

        As The client usually only has a vague idea of exactly what is required from the software product, this WM has difficulty accommodating the natural uncertainty that exists at the beginning of the project.

        The customer only sees a working version of the product after it has been coded. This may result in disaster if any undetected problems are precipitated to this stage.

4.2.2 Prototyping Model

A prototype is an original type, form, or instance of something serving as a typical example, basis, or standard for other things of the same category. This model consists of building an experimental system rapidly and inexpensively for end users to evaluate. Prototype is a working version of an information system but it meant to be only a preliminary model. Once, operational prototype will be refined until it confirms, precisely to user requirement.The process of developing a prototype can be broken down into following steps:

Step 1: Identify the user’s requirement

The system designer (usually an information system specialist) work with the user along enough to capture basic information needs.

Fig: 4.3 Prototyping

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Step 2 : Develop a working prototype

The system designer creates a working prototype quickly, using fourth generation software, iterative multimedia, computer aided design(CAD) tools.

Step 3: Use the prototype

The user is encouraged to work with the system in order to determine how well the prototype meets his/her needs and to make suggestion for improving the prototype.

Step 4: Revise and enhance the prototype

The system builder notes all changes the user requests and refines the prototype accordingly. After the prototype has been revised, the cycle returns to step 3. Step 3 and step 4 are repeated till users are not satisfied.

When no more iteration is required, the approved prototype then becomes operational prototype that furnishes the final specification for the operations.The process involved in this prototype can be summarized in figure. This model helps to counter problem in waterfall model..

4.2.2.1 Advantages May provide the proof of concept necessary to attract funding Early visibility of the prototype gives users an idea of what the final system looks like

Encourages active participation among users and producer

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Enables a higher output for user

Cost effective (Development costs reduced)

Increases system development speed

Assists to identify any problems with the efficacy of earlier design, requirements analysis and coding activities

Helps to refine the potential risks associated with the delivery of the system being developed

Various aspects can be tested and quicker feedback can be got from the user

Helps to deliver the product in quality easily

User interaction available in during development cycle of prototype

4.2.2.2 Disadvantages Producer might produce a system inadequate for overall organization needs User can get too involved whereas the program cannot be to a high standard

Structure of system can be damaged since many changes could be made

Producer might get too attached to it (might cause legal involvement)

Not suitable for large applications

4.2.3 Spiral Model

The spiral model is a software development process combining elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. Also known as the spiral lifecycle model, it is a systems development method (SDM) used in information technology (IT). This model of development combines the features of the prototyping model and the waterfall model. The spiral model is intended for large, expensive and complicated projects.

The spiral model was defined by Barry Boehm in his 1988 article "A Spiral Model of Software Development and Enhancement". This model was not the first model to discuss iterative development, but it was the first model to explain why the iteration matters.

As originally envisioned, the iterations were typically 6 months to 2 years long. Each phase starts with a design goal and ends with the client (who may be internal) reviewing the progress thus far. Analysis and engineering efforts are applied at each phase of the project, with an eye toward the end goal of the project.

The steps in the spiral model looks like in figure 4.4 and can be generalized as follows:

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1. The new system requirements are defined in as much detail as possible. This usually involves interviewing a number of users representing all the external or internal users and other aspects of the existing system.

2. A preliminary design is created for the new system.

3. A first prototype of the new system is constructed from the preliminary design. This is usually a scaled-down system, and represents an approximation of the characteristics of the final product.

4. A second prototype is evolved by a fourfold procedure:

Evaluating the first prototype in terms of its strengths, weaknesses, and risks;

Defining the requirements of the second prototype;

Planning and Designing the second prototype;

Constructing and Testing the second prototype.

AdvantagesPromotes quality assurance through prototyping at each stage in systems development

Fig: 4.4 Spiral Model

4.2.4 Rapid Application Development (RAD)

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The term rapid application development (RAD) is used to describe the process of creating workable systems much in a short period of time. This makes the use of object oriented software tools, reusable software, prototyping, and fourth generation tools. RAD can also include the use of visual programming and other tools for building graphical interfaces, iterative prototyping of key system elements, the automation of program code generation, and close teamwork between end users and information system specialists. Simple systems can be assembled from prebuilt components. The process doesn’t have to be sequential, and key parts of development can occur simultaneously.

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Chapter –Five

Graphical Representations

5.1 System Concepts

A system in a simplest form can be defined as a group of interrelated or interacting elements forming a unified whole. It is a group of interrelated components working together toward a common goal by accepting inputs and producing outputs in an organized transformation process. A system is defined and determined by its boundaries and objectives. A large system can be split or decomposed into smaller sub-system up to a certain level.

5.2 System Types

There are various classification of a system. Some of them are briefly discussed below:

Black Box System : If the process of input transformation is not visible and understandable, the system is said to be the black box system.

Deterministic System : If in a system, inputs processes and output can be known with certainty then it is called as deterministic system.

Probabilistic system : A system is called probabilistic system if outputs can only be predicted in probability form.

Closed system : If the system doesn’t interact with the environment, then it is called closed system.

Open system : If the system has exchange with the environment and is influenced by the environment, then it is called open system.

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ProcessingInputs:

Product data

Employee data

Customer data

Outputs:

Sales report

Inventory report

Customer profile

Governmen rules and Regulation

Political uncertainties, strikes, lockouts

Economic Scenario

Socio-cultural Influences

Feedback

Fig 5.1 System diagram

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5.3 Data Flow Diagram (DFD)

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Fig 5.2: Data Flow Diagram of Inventory Management

Purchase

Receipt

Inventory data

Sales data

Formatted Sales data

Formatted Inventory data

Product data

Inventory added

Inventory

Product data

Bar code

Inventory data

Summarized inventory report

Customer

2.0

Enter Purchase data and generate

receipt

3.0

Update sales record

4.0

Update inventory

used

1.0

Update inventory

added and assign

barcode

Store

D1

5.0

Generate inventory level

report

Supervisor

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Property Rights and Obligations

Quality of Life

Health Problems

Systems Quality

Accountability and control

Information Rights and Obligations

Business/IT ethical, social and plitical

issues

Individual Political

Social

Fig 6.1: Model of Social, Ethical and political Issues

Chapter-Six

Ethical and Social Issues in Information System

6.1 Introduction

Ethics means the way which guide individuals to judge their behaviors as right or wrong. New different ethical issues are raised by the information systems for both individual and societies as information system create new opportunities for individuals and make easy in lots of issues which make subject of legal operations. With the rise of the Internet and electronic commerce it has been easy to assemble, integrate, and distribute information, unleashing information about customers. This has raised the issues of the protection of personal privacy, and the protection of intellectual property.

Ethical issues raised by information systems are:

Making accountability for the consequences of information systems. Setting up standards to maintain system quality that protect the safety of the individual

society Maintain values and

institutions which are essential for the quality of life in an information society.

The use of information technologies in business has had major impacts on society and thus raises ethical issues in the areas of crime, privacy, individuality, employment, health, and working conditions. As a business professional, the manager in an organization should consider the moral, ethical, political and social issues that affect the organization as well as the effect of organizations to such aspects. A model of thinking about ethical, social and political issue can be shown in figure 6.1 with its explanation below:

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Information Rights and Obligations: What information rights do individuals and organizations posses with respect to information about themselves? What they protect? What obligations do individuals and organizations have concerning this information?

Property Rights and Obligations: How will traditional Intellectual Property Rights be protected in a digital society in which tracing and accounting for ownership is difficult and ignoring such property rights is so easy

Accountability And Control : Who can and will be held accountable and liable for the harm done to individual and collective information and property rights?

System Quality: What standards of data and system quality should we demand to protect individual rights and safety of society?

Quality Of Life: What values should be preserved in information and knowledge based society? Which institutions should we protect from violation? Which cultural values and practices are supposed by the new information technology?

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