Chapter 5 - Design and Implementation

Abstract

This chapter discusses the major tasks of design and implementation, such as producing a detailed design, writing design documents, implementing base levels, and producing product kits. When preliminary planning and design are complete, the development team turns to the tasks of creating the detailed design, implementing it, and testing the software. The tasks entail building source code modules, then compiling, linking, and executing the resulting images. User documentation is created, and software tests are conducted to ensure that the implementation operates correctly. Often, the system implementation consists of a series of stages or base levels in which each adds more and more of the required functionality. As the team implements and tests each base level, they may discover unforeseen problems in implementing the design, meaning that specifications and designs might require revision. If so, the programs, the tests, and the user documentation must also accurately reflect changes in requirements or designs. The project team must analyze the structure and performance of the software in this phase. Reviews of the design, code, tests, and documentation are held frequently. Other groups are given copies of the software to determine how well the program works under controlled conditions. Performance analysis ensures that the system will meet certain customer-environment requirements. When this phase is successfully completed, the project should have software that works.