Prototype Model in Software Engineering

The Prototyping Model is a systems development method (SDM) in which a prototype (an early approximation of a final system or product) is built, tested, and then reworked as necessary until an acceptable prototype is finally achieved from which the complete system or product can now be developed. This model works best in scenarios where not all of the project requirements are known in detail ahead of time. It is an iterative, trial-and-error process that takes place between the developers and the users.

In Prototyping Model initially the requirement gathering is done. Developer and customer define overall objectives; identify areas needing more requirements gathering.

Then a quick design is prepared. This quick design represents what will be visible to user input and output format.

From the quick design prototyping is prepared. Customer or user evaluates the prototype in order to refine the requirements. Interactively prototype is turned for satisfying customer requirements.

 When working prototype is built, developer use existing program or fragments generators to throw away prototype and rebuild the system to high quality.

When to choose it?

1. Software application those are relatively easy to prototype. Almost always involve human machine interaction, the prototype model is suggested.
2. The general objective of software is defined but not detailed input, processing or output requirements. Then in such a case prototype model is useful.
3. When the developer is unsure of the efficiency of an algorithm or the adaptability of an operating system then prototype serves as a better choice.

Drawbacks of prototyping

1. In the first version itself, customer often wants “few fixes” rather than rebuilding of the system where as rebuilding of the new system maintenance high level of quality.
2. The first version may have some compromises.
3. Sometimes developers may make implementation compromise to get prototype working quickly. Later developer may become comfortable with compromises and forget why they are inappropriate.