The first stage is requirements analysis and specification, during which an attempt is made to arrive at an agreement concerning the detailed functionality of the system. As the project passes from one stage to the next, there are limited opportunities for going back and changing earlier decisions. One drawback of this approach is that potential users do not get a chance to interact with the system until very late in the system's life cycle. In the prototyping model, great emphasis is placed on producing a working model or prototype early during the life cycle of a system. The prototype is built for the purpose of arriving at a final specification of the functionality of the proposed system.
Potential users interact with the prototype early and often until the requirements are agreed upon.
This approach affords potential users the opportunity to interact with a prototype system early during the development cycle and long before the final system is designed and coded. In a memo dated December 11th of the year before last, Jan Anderson, a member of the original Robbie CX30 project team, bitterly attacked the decision of the project manager, Sam Reynolds, to employ the waterfall model. The Sentinel-Observer has obtained a copy of Anderson's memo, which is addressed to Reynolds, and Anderson verified the authenticity of the memo for this reporter. Reynolds fired Anderson on December 24th, just two weeks after she wrote the memo. The Anderson memo refers to an earlier meeting at which an angry exchange occurred relating to software development philosophy.