System DevelopmentInformation Systems for

Management 1

Chapter 9Chapter 9

System Development System Development

Outline

System Life Cycle (definition and phases)

System Planning (Automation, Business Process

Reengineering, Quality improvements -

Benchmarking)

System development methodologies

Installation/conversion methods

Systems success & risk factors

System DevelopmentInformation Systems for

Management 2

System DevelopmentInformation Systems for

Management 3

System Life Cycle

Installation

These activities/phases can be run in sequence or in iteration.

- Waterfall (structured) methodology

- Rapid methodologiesCo

nstr

uctio

n

Systems Planning

System DevelopmentInformation Systems for

Management 4System DevelopmentInformation Systems for

Management 4System DevelopmentInformation Systems for

Management 4

A Rapid Methodology - Prototyping

Strengths Weaknesses

Rapid and relatively inexpensive Inappropriate for large complex systems

Useful when requirements are uncertain or when end user interface is critical

Can gloss over steps in analysis, documentation and testing

Promotes user involvement

• An alternative to sequential development of systems

• Steps: • Identify basic user’s requirements• Develop an initial prototype• Test prototype & learn from users• Revise & enhance prototype

System DevelopmentInformation Systems for

Management 5

What organizational changes can be accomplished with new system:

Automation of manual tasks

Business Process Reengineering (BPR) - radical change of organization; process efficiency in focus

Quality improvements (Benchmarking – test of compliance with standards)

Systems Planning

System DevelopmentInformation Systems for

Management 6

Systems AnalysisAnalysis of organizational needs to be met with an information system focusing on

1. data/information as part of jobs and tasks and on data transformation - remember your entity-relationship diagrams? 2. processes working with data

Data analysis: define Information NeedsIdentifies who needs what information, and

when, where and how it is neededCollect business documentation, interview users & managers

System DevelopmentInformation Systems for

Management 7

Systems Design

Create IT-based solution for meeting organizational and

information needs

Design encompasses:

Data (usually some database)

Processes applied to data (functionality)

User Interface

Programming/Construction follows (can be putting

together of purchased software)

System DevelopmentInformation Systems for

Management 8

Testing

Testing – assessing quality of the developed system

Kinds of tests run based on small to large logic:

Unit testing (test each program)

System testing (tests IS as a whole; e.g., overload

the system)

Acceptance testing (final testing, evaluated by users)

System DevelopmentInformation Systems for

Management 9

Installation Methods

Direct cutoverNew system completely replaces old one

Parallel installationOld and new system used until the new proves reliable

Phased installationNew system introduced in stages by function

Pilot installationVariation of Phased - new system introduced to a limited area of the organization

System DevelopmentInformation Systems for

Management 10

Production Stage and Maintenance

System is being used for organizational needs

Operate the system

Evaluate the system

Modify the system as needed (Maintenance; e.g.,

larger data

storage needed or queries answering new questions)