Prototype Model

A prototype is a working model that is functionally equivalent to a component of the product. In many instances the client only has a general view of what is expected from the software product. In the case of absence of detailed information regarding the input to the system, the processing needs and the output requirements, the prototyping model may be employed.
This model reflects increase the flexibility of the development process by allowing the client to interact and experiment with a working product model. The developmental process only continues once the client is satisfied with the functioning of the prototype. That time the developer come to know about clients real need.

Software prototyping

Software prototyping, is the creation of Beta versions, i.e., incomplete versions of the software program being developed.A prototype only contains a small subset of the features of the actual program, and the implementation is also not called robust.The purpose of a prototype is to allow users of the software to evaluate the design of the actual product by actually trying them out.

Benefits:
The software developer can obtain early feedback from the users. The client can compare if the software matches the software specification, according to which the software program is built. It will help to determine the developer to kept a goal of his own for the project.

Process of prototyping involves the following steps

1)Identify basic requirements
Determine basic requirements including the input and output information desired. Details, such as security, can typically be ignored.
2)Develop Initial Prototype
The initial prototype is developed that includes only user interfaces.
3) Review
The customers, including end-users, examine the prototype and provide feedback on additions or changes.
4) Revise and Enhancing the Prototype
Using the feedback both the specifications and the prototype can be improved.

Classifications

it can be classified as throwaway prototyping and evolutionary prototyping
Throwaway or Rapid Prototyping refers to the creation of a model that will eventually be discarded rather than becoming part of the finally delivered software.
The main goal when using Evolutionary Prototyping is to build a very robust prototype in a structured manner and constantly refine it.

Advantages

Reduced time and costs:
Improved and increased user involvement:

Disadvantages

Insufficient analysis:
User confusion of prototype and finished system:
Developer attachment to prototype:
Excessive development time of the prototype:
Expense of implementing prototyping:

Methods

Dynamic Systems Development Method (DSDM) is a framework for delivering business solutions that relies heavily upon prototyping as a core technique, and is itself ISO 9001 approved.
The four categories of prototypes as recommended by DSDM are:

• Business prototypes.
• Usability prototypes.
• Performance and capacity prototypes.
• Capability/technique prototypes.

Tools

Visual basic etc.