RAD - Rapid Application Development
Rapid Application Development
- Shortens the projects duration (less than 6 months)
- User involved throughout the whole design process
- End user is able to see what the end product would look like and how its functions before any functions are created
- Requirements don’t change- remain static
- Provide helpful feedback before actually creating the system
RAD has two main features:
- JAD - Joint application development- develop a set of requirements and these don’t change before the systems implemented
- Time-boxing - requirements defined in small chunks
Benefits and Limitations of RAD
- End user is involved at all stages, and the systems implemented within 6 months. Ensuring final system meets the requirements.
- End user doesn’t have to define all the requirements at the beginning of the process.
- May meet the requirements but functionality may not be acceptable. E.g. system tested using small amount of end users may function well however may not function well with many end users when using the system concurrently.
- Project manager needs to keep tight control over the development process and the team, time scale needs to be adhered to or else the solution may not be developed within 6 months deadline.
First attempt at the design representing some aspect of the full system, for instance a mock-up of the graphical user interface.
Two ways of prototyping:
Evolutionary - prototype created and evaluated by end user, second prototype created according to the feedback from the first and like this it continues evolving until they’ve agreed on a product solution
Throw-away - prototype created and evaluated by end user, however it isn't used in the final solution, it's thrown away. Users can give and receive quick feedback
Benefits and Limitations of Prototyping
- Reduced time and costs- improves quality of requirements and specifications, changed detected before creating new system thus cost effective
- Improved and increased user involvement- users interact with a prototype thus gain better feedback early in the project
- Confusion between prototype and the finished system- the end user may think the prototype that needs throwing away is the final system that needs to be finished. User can get attracted to features that were used but are now taken out
- Excessive developmental time of the prototype- prototypes should be done quickly, excessive time can be spent making it complex increasing the cost