System prototyping performs the analysis, design, and implementation phases
concurrently in order to quickly develop a simplified version of the proposed system
and give it to the users for evaluation and feedback. (See Figure 2-6). The system
prototype is a “quick and dirty” version of the system and provides minimal
features. Following reaction and comments from the users, the developers reanalyze,
redesign, and reimplement a second prototype that corrects deficiencies and
adds more features. This cycle continues until the analysts, users, and sponsor agree
that the prototype provides enough functionality to be installed and used in the
organization. System prototyping very quickly provides a system for users to evaluate
and reassures users that progress is being made. The approach is very useful
when users have difficulty expressing requirements for the system. A disadvantage,
however, is the lack of careful, methodical analysis prior to making design and
implementation decisions. System prototypes may have some fundamental design
limitations that are a direct result of an inadequate understanding of the system’s
true requirements early in the project.