ISM Session 2

7/31/2019 ISM Session 2

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IS Development ConceptsIS for Managers


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Using the Systems Approach in Problem

SolvingThe systems approach to problem solvinginvolves the following steps:

Define the problem

Gather data describing the problem

Identify alternative solutions

Evaluate the alternatives

Select and implement the best alternative

Follow up to determine if the solution is

working


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Obtaining Information System

Organizations can obtain new informationsystems in one of the following ways:

Build the IS themselves Buy a prepackaged system from a software

development company or consulting firm

Ask an outside organization or consultantcustom build a system to an organizationsspecification


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Information Systems Plan

1.PURPOSE OF THE PLAN:overview ofplan contents, changes in current situation,firms strategic plan, current organization,key business processes, managementstrategy

2. STRATEGIC BUSINESSPLAN: current

situation, current organization, changingenvironments, major goals of plan


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Contd.

3. CURRENT SYSTEMS: major systems

supporting business functions & processes,major current capabilities (hardware,software, database, telecommunications),difficulties meeting requirements, anticipated

future demands

4. NEW DEVELOPMENTS:new systemprojects (project descriptions, businessrationale), new capabilities required(hardware, software, database,telecommunications, internet)


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Contd.

5. MANAGEMENT STRATEGY:acquisition

plans, milestones & timing, organizationalrealignment, internal reorganization,management controls, major traininginitiatives, personnel strategy

6. IMPLEMENTATION PLAN:anticipateddifficulties, progress reports

7. BUDGET REQUIREMENTS:requirements,potential savings, financing, acquisition


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CRITICAL SUCCESS FACTORS (CSFs)

Small number, easily identifiable

operational goals

Shaped by industry, manager, environment

Believed to assure firms success

Used to determine organizations

information requirements


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CRITICAL SUCCESS FACTORS

example:PROFIT CONCERN

GOALS (AUTOMOBILE INDUSTRY):

earnings per share, return on investment,

market share, new product

CSF: styling, quality dealer system, cost

control, energy standards


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CRITICAL SUCCESS FACTORS

example:NONPROFIT CONCERN

GOALS (HOSPITAL): Excellent health

care, meeting government regulations,future health needs

CSF: Regional integration with other

hospitals, efficient use of resources,improved monitoring of regulations


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Spectrum of Organizational Change

AUTOMATION: using technology to

perform tasks efficiently / effectively

RATIONALIZATION OF PROCEDURES:

streamline sops; eliminate bottlenecks

BUSINESS REENGINEERING: radical

redesign of processes to improve cost,

quality, service; maximize benefits of

technology

Paradigm shift


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Paradigm Shift

PARADIGM: A complete mental model of

how a complex system functions

A PARADIGM SHIFT: Involves rethinking

the nature of the business, the organization;

a complete reconception of how the system

should function


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BUSINESS PROCESS REENGINEERING (BPR)

REENGINEERING: Redesigning business

processes to lower cost, speed development WORK-FLOW MANAGEMENT:

Streamlining process to move documents

easily, efficiently


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Effective Reengineering Steps

1. Develop business vision, process objectives

2. Identify process to be redesigned

3. Understand, measure performance ofexisting processes

4. Identify opportunities for applying

information technology5. Build prototype of new process

S t D l t A O i


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Systems Development: An Overview

Activities involved in producing an IS solution toan organizational problem or opportunity are

called systems development This is a structured kind of problem solving with

distinct activities moving from one step to the

other The process of designing, building and

maintaining information systems is known assystems analysis and design

The term systems development life cycle (SDLC)is used to describe the life of an informationsystem right from its conception till its

retirement


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Contd.

Large complex problems are decomposed intosmaller once to arrive at better solutions

These smaller problems are solved through small

computer programs The final system is built by combining these

smaller computer program

Systems development process starts whenmanagement realize that a particular business

system needs improvement


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Systems Analysis

The main focus of this phase is to have athorough understanding of theorganizations current way of doing thingsin the area for which the system is beingbuilt

The first sub phase of this phase isdetermining systems requirements that is

done by working closely with the users anddetermining what is expected from the newsystem


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Contd.

Once these requirements are collected,

information are organized using data, processesand logic modeling tools

Systems requirements are collected through

interviews, questionnaires, observations,document analysis etc

This phase also includes feasibility study to

determine if the solution being developed isfeasible financially technically and

organizationally


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Contd.

Analysis of problem to be solved with an

Information system

Feasibility study: can problem be solved within

constraints?


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FEASIBILITY

TECHNICAL:Assess hardware, software,

technical resources

ECONOMIC: Will benefits outweigh costs?

OPERATIONAL:Is solution desirable

within existing conditions?

INFORMATION REQUIREMENTS:Detailed statement of new system needs


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Systems Design

This phase suggests as to how the system would meetthe information requirements determined in theanalysis phase

So the system is designed based on the detailsprovided through the previous phase

At this stage, following activities are performed:

- Designing forms and reports

- Designing interfaces and dialogues

- Designing databases and files

- Designing processing and logic


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Contd.

Details how system will meet needs: LOGICAL DESIGN:components, data as

needed by applications

PHYSICAL DESIGN:physical location ofcomponents and data


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DESIGN SPECIFICATIONS

OUTPUT: Medium, content, timing

INPUT: Origins, flow, data entry

USER INTERFACE: Simplicity, efficiency, logic,feedback, errors

DATABASE DESIGN: Logical data relations,volume, speed requirements, file organization &design, record specifications

PROCESSING:Computations, program

modules, required reports, timing of outputs MANUAL PROCEDURES: What activities, who

performs them, how, where


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DESIGN SPECIFICATIONS

CONTROLS:Input, processing, output,procedural

SECURITY:Access controls, catastrophe plans,

audit trails DOCUMENTATION:Operations, systems, user

CONVERSION: Transfer files, initiate newprocedures, select testing modules, cut over to new

system TRAINING: Select training techniques, develop

training modules, identify training facilities


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Design Specifications

ORGANIZATIONAL CHANGES: Task

redesign, job design, process design,

organization structure design, reportingrelationships


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Testing

This stage is very important to ensure that the

system developed is capable of producing the right

results under known circumstances

This involves the following aspects:

- Unit testing

- System testing

- Acceptance testing


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Conversion

At this stage the organization switches over to the new

system from the old one

One of the following approaches can be used for this:

- Parallel

- Direct cutover

- Pilot study

- Phased This also involves the training of the users and proper

documentation of the system


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Production and Maintenance

After conversion, the system is in production

The system is reviewed here technically as well as by

the end users in order to determine the requirement ofany modifications


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Approaches to IS Development

Traditional Systems Development Approach

Prototyping

Rapid Application Development

Object Oriented Approach


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Steps in Systems Development Process

Systems Development Life Cycle (SDLC) has the

following five primary phases:

System identification, selection and planning

System analysis

System design

System implementation

System maintenance


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Systems Identification, Selection and Planning

The main goal of systems identification and selection isto identify and select a development project from allprojects that could be performed

The main focus is the ease with which existing hardwareand systems can be integrated with the proposed system

Other focus area include: cost, duration, complexity andrisk


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Contd.

In the project planning phase the analysts work with thecustomers to collect a broad range of information togain an understanding of project size, potential benefitsand costs and other relevant factors

Once all these information are collected and analyzed, asummary planning document is reviewed and comparedwith other projects

Once the project is accepted, systems analysis starts


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System Implementation

This phase focuses on transforming the system designinto a working information system that can be used bythe organization

The activities included are software programming and

testing

Besides this other activities include preparing theorganization fir using the new is through systemconversion, documentation, user training and support


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Approaches of System Implementation

Parallel

Direct cutover

Pilot study

Phased approach

Documentation

S t M i t


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System Maintenance

In this phase, maintenance requests from thesystem users are collected

If the request is analyzed as to how the proposedchange might alter the system and what business

benefits might result from that change If the change request is approved, a system

change is designed and implemented

Like initial development of the system,implemented changes are reviewed and testedbefore implementation

Contd


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Contd.

The system maintenance process is parallel tothe process of initial development of the is

During this phase the largest part of thesystems development effort occurs

Maintenance activity could be of one of the

following types:- Corrective maintenance

- Adaptive maintenance

- Perfective maintenance- Preventive maintenance

Prototyping : An Overview


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Prototyping : An Overview

Prototype refers to a working model of aninformation system application

But it does not contain all the features orperform all the necessary functions of the finalsystem

However, it includes sufficient elements toenable individuals to determine what they likeor dont like and also to identify features to be

added or changed It is a process of building experimental system

quickly and inexpensively for demonstrationand evaluation


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Characteristics of Prototypes The prototype is a live, working application The purpose is to test the assumptions made

by analysts and the users about requiredsystem features

These are created quickly

They evolve through an iterative process

Prototypes are relatively inexpensive to

build


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Uses of Prototyping

Prototyping has the following two primary

uses:

Acts as an effective device for clarifyinguser requirements

It is used for verifying the feasibility of a

system design


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Steps in Prototype Method

Identify known requirements

Develop working model

Use prototype

Review prototype

Repeat as needed


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Alternative Uses of Prototype

Abandon application

Implement prototype Redevelop prototype

Begin new prototype



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(RAD Approach)

Process for developing systems in short time

period

Uses prototyping, fourth-generation tools, and

close teamwork to move progressively closer to

correct design

A prototype is a small-scale representative or

working model of the proposed system

Iterative (or spiral) process of developing demo

or working models

Refined based upon user review


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Rapid Application Development (RAD)

Develop system rapidly:

Prototyping

4th GENERATION TOOLS

Close teamwork among users & specialists


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Contd.

Helps users definerequirements

Encourages active

user participation

Errors andomissions tend to be

detected earlier Builds enthusiasm

and acceptance forsystem

Prototype may meet

requirements but

not be best design

Systems

specifications

often not

adequately

spelled out

AdvantagesDisadvantages

The Object Oriented Approach


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The Object Oriented Approach

OO approachthis approach views an information

system as a collection of interacting objects that worktogether to accomplish tasks

Objecta component in the computer system that canrespond to messages.

OO Designdefining all of the types of objects necessaryto communicate with people and devices in the systemand refining the definition of each type of object so itcan be implemented with a specific language or

environment OO Programmingwriting statements in a

programming language to define what each type ofobject does, including the messages that objects send

and receive.


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Object - Oriented Software Development

De-emphasizes procedures

Shifts focus from models & data

Toobjects, which combine data &

procedures

Objects reusable

SYSTEM: classes, objects, relationshipsReduces development time & cost


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SYSTEMS DEVELOPMENT

DESCRIPTIONCORE ACTIVITY

SYSTEMS ANALYSIS

SYSTEMS DESIGN

PROGRAMMING

IDENTIFY PROBLEM(S)

SPECIFY SOLUTIONS

ESTABLISH INFORMATIONREQUIREMENTS

CREATE LOGICAL DESIGN SPECSCREATE PHYSICAL DESIGN SPECS

MANAGE TECHNICAL

REALIZATION OF SYSTEM

TRANSLATE DESIGN SPECS INTO

PROGRAM CODE


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SYSTEMS DEVELOPMENT

CORE ACTIVITY DESCRIPTION

SYSTEMS ANALYSIS

SYSTEMS DESIGN

PROGRAMMING

IDENTIFY PROBLEM(S)

SPECIFY SOLUTIONS

ESTABLISH INFORMATION

REQUIREMENTS

CREATE LOGICAL DESIGN SPECS

CREATE PHYSICAL DESIGN SPECSMANAGE TECHNICAL REALIZATION

OF SYSTEM

TRANSLATE DESIGN SPECS INTO

PROGRAM CODE


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SYSTEMS DEVELOPMENT

CORE ACTIVITY DESCRIPTION

TESTING

CONVERSION

MAINTENANCE

UNIT TEST

SYSTEMS TEST

ACCEPTANCE TEST

PLAN CONVERSION

PREPARE DOCUMENTATION

TRAIN USERS & TECHNICAL STAFF

OPERATE SYSTEM

EVALUATE SYSTEM

MODIFY SYSTEM

Documents

ISM Session 2