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 System Operationalize Prototype Develop Prototype Analyze problem Refine 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