Requirements Analysis and Program Specification. At the conceptual level, software development is comprised of several tasks. Of most importance, the design team must identify the goals of the design process. For example, in developing software to provide banking services through an automated teller machine (ATM), the design team will map out the necessary data, the desired functionality, and hardware and security constraints. They might develop tables or flowcharts to understand the flow of information needed to accomplish the various transactions. As another example, in developing software to run a law office, the designers must identify the various tasks that the computer program should handle— for example, billing clients, filing documents, ordering supplies, preparing budgets, and filing court documents. The design team would typically interview the prospective users of the software system about their needs and desires, study the way information flows in a law office, and develop a schematic representation of the tasks to be programmed. This abstract representation of tasks maps data inputs and outputs and assesses the hardware requirements for possible systems. Writing an application program is a complex and iterative process. While some programs are small and relatively simple to write, most modern programs involve thousands and even millions of lines of computer code. They may be written not by a single person but by teams of programmers working together over the course of months or years. Partly to facilitate collaborative work within teams, programmers some- times develop a flowchart to depict the logical structure of the program. This will not just show what the program is supposed to do but also how it will carry out the desired tasks. A sample flowchart for a computer program is reproduced as Figure 1. We should emphasize, however, that flow charts are merely conceptual aids, and are by no means a necessary part of programming.
