As show in Figure 19-1, four steps are involved in developing a prototype. The first step is to identify basic system requirements by meeting with users to agree on the size and scope of the system and to decide what the system should include and exclude. The developer and users also determine decision-making and transaction-processing outputs, as well as the input and data needed to produce these output. The emphasis is on what output should be produced rather that how it should be produced. The developer must ensure that users' expectations are realistic and their basic information requirements can be met. The designer uses the information requirements to develop cost, time, and feasibility estimates for alternations AIS solutions.