Prototyping

Introduction *Overview *What is the process *Changing roles of end users *What tools facilitate prototyping *Impact on traditional methodology

Overview *Development of working models to facilitate the specification of requirements *Prototypes developed in an interactive manner *Iterative process

Overview *Make development process faster and easier *Helps when requirements are difficult to define *Opens up development to end users

Process *May be used for both large and small applications Õlarge projects require traditional systems development but parts of the system may be prototyped *Application development tools are used to rapidly create a prototype

Process *A prototype is refined until user acceptance is gained *Prototyping is an iterative process, interactive process that combines steps of the traditional development cycle

Process Develop information system prototypes Revise prototypes to align with req’ts of end users Identify end user information req’ts Use and maintain the accepted system Prototyping Cycle Maintenance Cycle

Process *End users identify information needs Õassess feasibility of alternative information system solutions *End users/analysts use application development packages to build prototypes Õdesign and test information system components

Process *Information system prototypes are used, evaluated and modified Õrepeated until end users find it acceptable *Accepted information system can be modified easily Õmost system documentation is stored on disk

Changing roles of end user *Using application development tools users may undertake system development Õplay an active role in designing as opposed to specifying *Ownership and commitment to new systems *Management of change easier

Tools for prototyping *CASE - Computer Aided Software Engineering *Software tools for: Õbusiness planning Õproject management Õuser interface design Õsoftware development

Tools for prototyping *Components of Texas Instruments IEF (integrated CASE) product *Planning toolset Õinformation strategy planning (high level business perspective) *Analysis toolset Õcapture of detailed business requirements

Tools for prototyping *Design toolset Õdetailed specifications of system solution *Information integrator Õintegrates system specifications Õchecks specifications for consistency Õrecords specifications in repositories

Tools for prototyping *Front end and Back end tools Front end tools Enterprise models Data flow diagrams Data structure diagrams Entity relationship diagrams 4th generation languages Prototyping tools Back end tools Program flowcharts Program editors Program debuggers Code generators 4th generation languages Object orientated languages Prototyping tools System Developers

Impact on traditional methodology Systems Investigation Product: Feasibility Study Systems Analysis Systems Design Systems Implementation Systems Maintenance Product: Functional Requirements Product: Systems Spec Product: Operational System Product: Improved System Traditional Requirements Quick Design Building Prototype Customer Evaluation Refine Prototype Engineer Product Start Stop Prototyping