Prototyping process

Prototyping in the software process

Evolutionary prototyping

•         An approach to system development where an initial prototype is produced and refined through a number of stages to the final system

Throw-away prototyping

•         A prototype which is usually a practical implementation of the system is produced to help discover requirements problems and then discarded. The system is then developed using some other development process

Evolutionary prototyping

Ø Must be used for systems where the specification cannot be developed in advance e.g. AI systems and user interface systems

Ø Based on techniques which allow rapid system iterations

Ø Verification is impossible as there is no specification. Validation means demonstrating the adequacy of the system

Evolutionary prototyping advantages

Ø Accelerated delivery of the system

o   Rapid delivery and deployment are sometimes more important than functionality or long-term software maintainability

Ø User engagement with the system

o   Not only is the system more likely to meet user requirements, they are more likely to commit to the use of the system

Evolutionary prototyping problems

Ø Management problems

o   Existing management processes assume a waterfall model of development

o   Specialist skills are required which may not be available in all development teams

Ø Maintenance problems

o   Continual change tends to corrupt system structure so long-term maintenance is expensive

Contractual problems