Prototyping Model

Prototyping paradigm used in following scenarios:

• A customer defines a set of objectives which are ambiguous.
• The developer may not guess the efficiency of an algorithm and the capability of an operating system correctly.

Requirements Gathering:

The prototyping paradigm starts with requirements gathering stage. Developer and customer meet and define the overall objectives for the software, identify whatever requirements are known, and outline areas where further definition is mandatory.

Design:

A "quick design" then occurs. The quick design focuses on a representation of those aspects of the software that will be visible to the customer/user.

Build,Test and Deploy:

The quick design leads to the construction of a prototype. The prototype is evaluated by the customer/user and used to refine requirements for the software to be developed. Iteration occurs as the prototype is tuned to satisfy the needs of the customer, while at the same time enabling the developer to better understand what needs to be done.

Advantages:

The prototype serves as a mechanism for identifying software requirements.If a working prototype is built, the developer attempts to use existing program fragments or applies tools that enable working programs to be generated quickly.

Disadvantages:

• The first system built is barely usable.
• It requires good planning ,design and careful partitioning of the product.
• It requires well-defined interfaces between the increments.
• It requires early definition of fully functional product to define the requirements.
• Slow
• Big
• Throwaway

Reasons for Failure:

• Developer's implementation compromise to get a prototype working quickly.
• Inappropriate operating system or programming language
• inefficient algorithm