Chapter 14

Systems Development

Agenda

• Reasons for Change• System Development Life Cycle (SDLC)• Prototyping

• Rapid Application Development (RAD)

• Object Oriented Development

• End User Development

• Issues

• FHC System Proposal

Reasons for Change

• Deterioration (legacy systems)

• Technology

• User expectations

• Keep up with competition

• External forces– Merger / takeover– Government regulation

IT Life Cycle

• Analysis and design

• Implementation

• Maintenance

• Deterioration or obsolete

Development Method

• System development life cycle (SDLC)

• Prototyping

• Rapid application development (RAD)

• Object oriented development

• End user development

• Outsourcing

Agenda

• Reasons for Change

• System Development Life Cycle (SDLC)

• Prototyping

• Rapid Application Development (RAD)

• Object Oriented Development

• End User Development

• Issues

• FHC System Proposal

System Development Life Cycle (SDLC)

• Distinct IS project segments

• Different with each organization

• Each segment has– start and end dates– deliverable

System Development Life Cycle

• Feasibility study– Technology, Economics, organizational factors,

legal, ethical, and other constraints

• Analysis and design– User requirements: input, output, storage

• Acquisition or development– Programming, testing, documenting

System Development Life Cycle

• Implementation– Parallel conversion, direct cutover, pilot

conversion, phased or modular conversion

• Operation• Post-audit

– System performance

• Maintenance– Minor changes

Agenda

• Reasons for Change

• System Development Life Cycle (SDLC)

• Prototyping

• Rapid Application Development (RAD)

• Object Oriented Development

• End User Development

• Issues

• FHC System Proposal

Prototyping

• Model of final IS

• Reasons– 4GLs– PCs– Failure of classic approach

Prototype Life Cycle

Complete SystemComplete SystemComplete SystemComplete System

Operationalize PrototypeOperationalize PrototypeOperationalize PrototypeOperationalize Prototype

Develop Prototype Develop Prototype Develop Prototype Develop Prototype

Analyze problemAnalyze problemAnalyze problemAnalyze problem

Refine PrototypeRefine PrototypeRefine PrototypeRefine Prototype

Prototyping Types

• Operational prototype or production prototype

• Throwaway prototype

Advantages

• User oriented– What the user sees– Not enigmatic diagrams

• Quicker error feedback

• Earlier training

Disadvantages

• User expectations

• Bypass analysis

• Documentation

• Never ending

Agenda

• Reasons for Change

• System Development Life Cycle (SDLC)

• Prototyping

• Rapid Application Development (RAD)

• Object Oriented Development

• End User Development

• Issues

• FHC System Proposal

Rapid Application Development

• Special case of Prototyping

• Components– GUI development environment– Reusable components– Code generator– Object oriented programming language

Advantages

• Speed

• Portability

• Maintainability and modifiability

• Data oriented systems

Disadvantages

• Never ending

• Lack of documentation

• Inadequate analysis

Agenda

• Reasons for Change

• System Development Life Cycle (SDLC)

• Prototyping

• Rapid Application Development (RAD)

• Objective Oriented Development

• End User Development

• Issues

• FHC System Proposal

Object Oriented Development

• Reusable IS components

• Small, self-contained program modules

• Includes– Operations– Data

Advantages

• Easier to build and maintain (object)• Reusable codes• Flexible for adding and changing objects• User oriented• Increase productivity and quality (programmer)• Increase productivity and quality• Web application

Disadvantage

• Complex

• Lack of experts

Agenda

• Reasons for Change

• System Development Life Cycle (SDLC)

• Prototyping

• Rapid Application Development (RAD)

• Object Oriented Development

• End User Development

• Issues

• FHC System Proposal

End User Development

• Reasons– Powerful PC– Cheaper hardware– Software capability– Computer literate – IS backlog– Small application

Advantages

• User control

• Business oriented

• Cost saving

• Development speed

Disadvantages

• Cost (hardware and software)

• Lack of analysis

• Lack of testing

• No documentation

• Duplication effort

• Security

• Backup and recovery

Points to Remember

• Reasons for Change

• System Development Life Cycle (SDLC)

• Prototyping

• Rapid Application Development (RAD)

• Object Oriented Development

• End User Development

Discussion Questions

• Will applications programmers and systems analysts become nothing more than evaluators of packaged software?

• How do you measure “System Effectiveness” in your organization?– How can you tell when a system is

“successful”?– “unsuccessful”?– How do you decide that a system needs

rework?

Assignment

• Review chapters 8-14 & technology

• Read chapter 15

• Group assignment

• Research paper