systems devt

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References:

Laudon, K. C. and Laudon, J. P., Management

Information Systems: Managing the Digital Firm,

12th edition, Prentice-Hall, 2011.


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Our Main Focus

Why do systems development?

Understand the importance of linking the information

system to business needs.

Understand the need to create a system request. Understand how to assess technical, economic, and

organizational feasibility.

Understand Systems development Life Cycle and

phases.


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Why the need for systems

development?

System Development has three primary business

objectives:

- Ensure the delivery of high quality systems; - Provide strong management controls;

- Maximize productivity.


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Systems Development

Definition:

A conceptual model used in project

management that describes the stages involved

in an information system development project,

from an initial feasibility study through

maintenance of the completed application.


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Systems as Planned

Organizational Change

Building a new system is a kind of

organizational change

Includes changes in H/W, S/W, jobs,skill, management and organization

When we design new system

Need to redesign the organization

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Systems Analyst specialization

Most important skills:

Technical, business, analytical, interpersonal,

management, ethical, communication,

problem-solving, decision-making Roles:

Business analyst

Systems analyst Infrastructure analyst

Change management analyst

Project manager etc


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The activities that go into producing an

information system solution to an

organizational problem or opportunity are

called systems development


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Preliminary Investigation object

can be achieved in following steps:

Request Clarification

Feasibility study

Estimating Costs and Benefits

Request Approvals


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Feasibility Analysis involves 8 steps:

Form a project team & appoint a project leader.

Prepare system flowcharts.

Enumerate potential candidate system.

Describe & identify characteristics of candidatesystems.

Determine & evaluate performance & cost

effectiveness of each candidate system.

Weigh system performance & cost.

Select the best candidate system.

Prepare & report final project directive to

management.


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Feasibility Study Report

The report contains the following

sections:-

Cover letter Table of

Overview

Detailed findings

Economic justification

Recommendations & conclusions

Appendixes


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Types of feasibility study:

There are six types of feasibility:

Technical feasibility

Economic feasibility

Operational feasibility

Legal and Political Feasibility

Schedule Feasibility


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System Analysis or Requirement

Analysis:

Thisphaseof System Development is

being completed in following step:

Collection of data and facts

Analysis of Present System

Analysis of Proposed system


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Collection of Data & Facts:

1. Documents review:

2. Questionnaires:

3. Interviews:

4. Observation.


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Analysis of Present

System

Review of Historical Aspects of organization

Analyze Present inputs to the system

Review of all data file maintained irrespective of

online or offline

Review methods, procedures & data

communications

Analyze Present outputs of system

Review internal controls

Model the existing physical system and logical

system

Undertake overall analysis of present system


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Analysis of Proposed

System

Output / Reports

Maintenance of Database

Data Inputting Process

Methods and Procedures to show the

relationship between Input and Output

Work volume including peak periodwork volume


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System Design

The overall plan or model for that system

Consists of all the specifications that give

the system its form and structure What makes one design superior to others

is the ease and efficiency with which itfulfills user requirements within a specific

set of technical, organizational, financial,and time constraints


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Programming (Software Coding)

System specifications that were prepared

during the design stage are translated into

software program code


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System Testing

Exhaustive and thorough testingmust be conducted to ascertainwhether the system produces the

right resultse.g., Unit testing, system testing,

UAT

Systems development teamworks with users to devise asystematic test plan

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Conversion

Process of changing from the oldsystem to the new system

e.g., parallel strategy, directcutover, pilot study and phasedapproach

Detailed documentation showinghow the system works from both atechnical and end-user standpointis finalized during conversion stage

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Operation & Maintenance

After the new system is installed andconversion is complete, the system is saidto be in operation

During this stage, the system will bereviewed by both users and technicalspecialists to determine how well it hasmet its original objectives and to decide

whether any revisions or modifications arein order

Could conduct post-implementation audit

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Systems Development Process

Changes in hardware,software, documentation, orprocedures to a production

system to correct errors,meet new requirements, orimprove processingefficiency are termedmaintenance


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Alternative Systems Development

Approaches

System development life cycle (waterfall)method has defined, linear stages of systemsdevelopment and support

Prototyping model is used for developingprototype systems for soliciting userrequirements or building system


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The Waterfall Model

The waterfall model specifies a set of

sequential phases for software

development Each step cannot begin until the

previous step has been completed

anddocumented.

It is document-driven.


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The Limits of Waterfall Model

Inflexibility Cannot easily swim upstream

Over-Reliance on Documentation

Relies too much on documentation Detachment from Technology

One size methodology cannot fit all technologies.

Detachment from Marketplace Slow-paced methodology (Time consuming).

Detachment from the Profession Programming is not the same as assembly of cars or

baking breads, nor programmers work the same wayas manufacturing workers or bakers.


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Prototyping

Building experimental system rapidly and

inexpensively for end users to evaluate

Prototype: Working but preliminary version of

information system Approved prototype serves as template for final system

Steps in prototyping

1. Identify user requirements

2. Develop initial prototype

3. Use prototype

4. Revise and enhance prototype

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Prototyping Contd


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Advantages of prototyping

Useful if some uncertainty in requirements or

design solutions

Often used for end-user interface design

More likely to fulfill end-user requirements

Disadvantages

May gloss over essential steps May not accommodate large quantities of data or

large number of users

May not undergo full testing or documentation28

Prototyping Contd


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End-User Development

Some types of information systems can be developedby end users with little or no formal assistance fromtechnical specialists

Software tools (e.g., Microsoft Access and CrystalReport) enable end users to create reports or develop

software applications Adv:

Allowing users to specify the own business needsimproves requirements gathering

Contributing to higher level of user involvement and

satisfaction Disadv:

Higher organizational risks

Poor IS management and control


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means using an external vendor to build or

operate a firm's information systems.

The system may be custom built or may use asoftware package.

In either case, the work is done by the vendorrather than by the organization's internal

information systems staff.

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Outsourcing


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Outsourcing (cont.)

Advantages

Allows organization flexibility in IT needs

Disadvantages

Hidden costs, e.g.

Identifying and selecting vendor

Transitioning to vendor

Opening up proprietary business processes to

third party

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Rapid application development (RAD)

Process of creating workable systems in a very short periodof time

Utilizes techniques such as:

Visual programming and other tools for building graphicaluser interfaces

Iterative prototyping of key system elements

Automation of program code generation

Close teamwork among end users and information

systems specialists

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Used to accelerate generation of information

requirements and to develop initial systems design

Brings end users and information systems

specialists together in interactive session to discusssystems design

Can significantly speed up design phase and involve

users at intense level

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Joint application design (JAD)


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Focuses on rapid delivery of working software by

breaking large project into several small sub-

projects

Subprojects Treated as separate, complete projects

Completed in short periods of time using iteration and

continuous feedback

Emphasizes face-to-face communication over

written documents, allowing collaboration and

faster decision making

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Agile development