Evolutionary Prototyping or Rapid Prototyping is a SDLC model used when developers are faced with undefined or rapidly changing requirements. Business Analysts tasked with documenting the requirements can find themselves frequently updating the project documentation and will have to stay focused and be in continual communication with developers to keep the documentation current and usable.
Similar to the spiral model, the most important requirements of the product are developed first, followed by the lower priority requirements with each milestone (prototype) created. With this approach you can present the prototype to the stakeholders to obtain clarification and acceptance of the requirements before you start the design phase. As the prototype evolves you eventually baseline a final set of requirements as agreed upon by the stakeholders until the final product is released.
During the evolutionary process it may sometimes be difficult to determine the timelines for a project plan. However, the use of this model may help the Business Analyst produce very detailed requirements so that the process is effective.
The four key steps involved with the Evolutionary Prototyping or Rapid Prototyping model are:
1. Initial Concept
Gather initial requirements
2. Create Prototype
3. Refine Prototyping
Describe all requirements in full detail while creating each milestone
4. Release final product
Develop a final solution based on prototype development