systems development - mis

8/3/2019 Systems Development - MIS

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Prof. Rushen Chahal

Systems Development


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Overview of Systems

Development Participants Initiating systems development

Information systems plann

ing

Establishing objectives for systemsdevelopment

Systems development and the Internet

Trends in systems development andenterprise resource planning


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Participants

Stakeholders Individuals/organizations who are beneficiaries of the

systems development effort

Systems analyst Professional who specializes in analyzing and

designing business systems

Users Individuals who interact with the system regularly

Programmer Individual responsible for modifying or developing

programs to satisfy user requirements


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Systems analyst

Managers

Vendors and suppliers

System stakeholders

Users Technical

specialists

Programmers


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Systems Analyst

A programmer or consultant who designs and manages the

development of business applications. Typically, systems

analysts are more involved in design issues than in day-to-day

coding. However, systems analyst is a somewhat arbitrary title,so different companies define the role differently.


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Typical Reasons to Initiate a

Systems Development Project

Desire to make more

effective use of information

Problems with existing systems

Desire to exploit new opportunities

Increasing competition

Organizational growth

Merger or acquisition

Change in market or

external environment

Perception of potential

benefit by individual

capable of initiating

change

Systems development

process initiated


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Planning

Information systems planning

The translation of strategicand organizational goals intosystems developmentinitiatives

Creative analysis

The investigation of newapproaches to existingproblems

Critic

al Analysis The unb iased and careful

questioning of whethersystem elements are relatedin the most effective orefficient ways

Strategic plan

IS planning

Systems development

initiatives


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Steps in IS Planning

Strategic plan

Developing overall objectives

Identify IS projects

Set priorities & select projects

Analyse resource requirements

Set schedules and deadlines

Develop IS planning document

Previously unplanned

system projects


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Establishing Objectives for

Systems Development Performance objectives Quality or usefulness of the output

The quality or usefulness of the format of the output

The speed at which the output is generated Cost objectives

Development costs

Costs related to the uniqueness of the system

applic

ation

Fixed investments in hardware and related equipment

On-going operating costs of the system


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Systems Development

and the Internet Applications being moved to the Internet Sales

Order placement

Product information access

Building a static Web site

Intranet tools NetDynamics

SilverStream

Web-Logic Novera

Netscape Communications


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Systems Development Life

Cycle Systems investigation

Problems and opportunities are identified

Systems analysis

Existing systems and work processes are studied Systems design

Def ines how the information system will do what it must doto solve the problem

Systems implementation

System components are assembled and the new ormodified system is placed into operation

Systems maintenance and review Ensures the system operates and is modified to keep up

with business changes

Its a

cycle


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Systems maintenanceand review

(evaluate results of solution)

Systems implementation

(place solution into effect)

Systems design

(select and plan best solution)

SystemsAnalysis

(understand solution)

Systems investigation

(understand problem)


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Cost to

make aparticular

change

Investigation Analysis Design Implementation Maintenance

and reviewTime


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Prototyping

Operational prototype

Accesses real data files, edits input data, makes necessarycomputations and comparisons, and produces real output

Non-operational prototype

A mo ckup or model that includes output and input specifications andformats

Rapid application development (RAD)

Employs tools, techniques, and methodologies designed to speedapplication development, automates source code generation, andfacilitates userinvolvement in design and development activities

Joint appl

ication de

velopment (JAD) Involves group meetings in which users, stakeholders, and IS

professionals work together to analyze existing systems, proposedsolutions, and define requirements for a new or modified system.


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Rapid Application Development

A programming system that enables programmers to quickly

build working programs. In general, RAD systems provide a

number of tools to help build graphical user interfaces that

would normally take a large development effort. Two of the most

popular RAD systems for Windows are Visual Basic and Delphi.

Historically, RAD systems have tended to emphasize reducing

development time, sometimes at the expense of generating

efficient executable code. Nowadays, though, many RAD

systems produce extremely fast code. Conversely, manytraditional programming environments now come with a number

of visual tools to aid development. Therefore, the line between

RAD systems and other development environments has become

blurred.


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Prototyping:

The Iterative Life CycleDetermine

requirements

Analysealternatives

Specify

design

Implementdesign

User review

Iteration 1

Determine

requirements

Analysealternatives

Specify

design

Implementdesign

User review

Iteration 2

Determine

requirements

Analysealternatives

Specify

design

Implementdesign

Changeover

Iteration 3 (final)


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General Model of Prototyping

Systems development initiated

Investigate and analyse problem

sufficiently to develop

workable solution

Develop prototype

Put prototype into operation

Refine and modify prototype

Complete component or system


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End-User Systems

Development Life Cycle End-user systems development life cycle Any systems development project in which

the primary effort is undertaken by a

combination of business managers and users


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Factors Affecting Systems

Development Success Managing change

Requires the ability to recognize existing or potentialproblems and deal with them before they become a

serious threat to the su

ccess of a new or mod

ifiedsystem

Use of project management tools Schedule

Milestone

Deadline Cr itical path

Program Evaluation Review Technique (PERT)

Gantt chart


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Selected Project Management

Software PackagesSoftware Vendor

BeachBox 98 NetSQL Partners

Job Order Management Software Inc.

OpenPlan Welcom

Project Microsoft

Project Scheduler Scitor Corp.

Super Project Computer Associates


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Use of Computer-Aided

Software Engineering (CASE)Tools

CASE tools automate tasks required in a systemdevelopment effort and enforces adherence to the SDLC

Upper CASE tools Tools that focus on activities associated with the early stages of

systems development

Lower CASE tools Tools that focus on the laterimplementation stage of systems

development

Integrated-CASE (I-CASE) tools Tools that provide links between upper- and lower-CASE

packages, allowing lower-CASE packages to generate programcode from upper-CASE package generated designs


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CASE

Short for ComputerAided Software Engineering, a category of software that provides a

development environment for programming teams. CASE systems offer tools to

automate, manage and simplify the development process. These can include tools for:

Summarizing initial requirements

Developing flow diagrams

Scheduling development tasks

Preparing documentation

Controlling software versions Developing program code

Various companies offer CASE software capable of supporting some or all of these

activities. While many CASE systems provide special support for object-oriented

programming, the term CASE can apply to any type of software evelopment

environment.


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ISO 9000

An international standard used by IS

departments to ensure quality standards

exist and are maintained in their products

and services


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Systems Investigation

Identify potential problems and opportunities and

consider them in light of the goals of the company

The investigation team

Managers and stakeholders IS personnel

Task

Undertake feasibility analysis

Establish system development goals

Select system development methodology

Prepare system development report


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Feasibility Analysis

Technical feasibility Can the hardware, software, and other system components be

acquired or developed to solve the problem?

Operational feasibility

Can the project be put into action or operation?

Schedule feasibility Can the project be completed in a reasonable amount of time?

Economic feasibility Does the project make financial sense?

Net present value The preferred approach for ranking competing projects and

determining economic feasibility


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The Systems Investigation

Report A report that summarizes the results of thesystems investigation and the process of

feasibility analysis and recommends a

course of action

Steering committee

An advisory group consisting of senior

management and users from the ISdepartment and other functional areas


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Systems Analysis

Typical table ofcontents from a systems

investigations report:

Table of Contents

1. Executive summary

2. Review of goals and objectives

3. System problems and opportunities

4. Project feasibility

5. Project costs

6. Projects benefits

7. Recommendations


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Sources of Data

Internal Sources

Users, stakeholders, managers

Organization charts

Forms and documents

Procedure manuals and policies

Financial reports

IS manuals

Other measures of business

processes

External Sources

Customers

Suppliers

Stockholders

Government agencies

Competitors

Outside groups Journals, etc.

Consultants


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Data Collection

Structured Interview

Unstructured Interview

Direct Observation

Questionnaires

Statistical Sampling

Identify data sources

Data collection

Follow-up & clarification


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Data Analysis

Data analysis Manipulating collected data so that it is usable for the

development team members participating in systems analysis

Data modeling

A commonly accepted approach to modeling organizationalobjects and associations that employ both text and graphics

E.g, ER (entity relationship) diagrams

Activity modeling A method to describe related objects, associations, and activities

Data flow diagram A d iagram that models objects, associations, and activities by

describing how data can flow between and around them


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ER Example

PlayMember Game of Golf

MID

Name Address

Date

paid Date Time Score

1 g

MID


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Data Flow Diagram

Schematic description of business

processes

Premise: for every activity there is some

communication, transference, for flow that can

be described as a data element

DFDs show logical sequences (not physical

processes)


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Entity symbol Data-flow lineProcess

symbolData-flow line Data store

Member

Member

Member

Assign

Tee time

Checkmember

in

Sortscores

Calculatehandicap

Schedule

Member card

Scores

Tee time

Reservation request

Course access

Member ID

Score card

Handicap

Available times

Group information

Member

tee time

Date

Score card

Tee time


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Application Flowchart

Charts that show relationships among

applications or systems

Order processing

application

Inventory control

application

Invoicing

application

Marketing analysis

application


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Grid Charts

A table that shows relationships among the

various aspects of a systems development

effortDatabaseapplications

Customer

database

Inventory

database

Supplier

database

Accounts receivable

database

Order processing

applications

Inventory control

application

Marketing analysis

application

Invoicing

application

X X

X X

X X

X

X


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Screen Layout Charts

May be tailored for

Frequent users who require little descriptive

information, or

Infrequent users who require more descriptive

information


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ITEM NO. QTY UNIT PRICE DOLLARS DISCOUNTSXXXXXXX XXXX XX XXXXX XXXXXX XX XX XX

XXXXXXX XXXX XX XXXXX XXXXXX XX XX XX






ORDER ENTRY

ORDER

NO.

CUSTOMER

NO.

SALES

PERSON REGION COMMISSION

NET

DOLLARS

XXXXX XXXXX XXXXX XXX XXX XXXXX

For frequent users


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Which online option would you like to perform?(Please enter an X to make a selection)

_DATA ENTRY Enter transaction and report

requests for later processing

_RETRIEVALS Review online information from the

database: bill of materials,

where-used, routing, item data

For infrequent users


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The Systems Analysis Report

Strength and weaknesses of existing

system from a stakeholders perspective

User/stakeholder requirements for the newsystem

Organizational requirements

Desc

ri

pti

on of what newi

nformati

onsystems should do to solve the problem


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Typical Table of Contents for

a Report on an ExistingSystem

Johnson & Flores, Inc.

Systems Analysis Report

TABLE OF CONTENTS

Background Information

Problem or Need Statement

Data Collection

Data and Requirements AnalysisRecommendations

Appendixes of Documents, Tables, and Charts

Glossary of Terms