ABSTRACT
The module requirements specification is the low-level design specification for the system. At this level, we are concerned for the first time about implementing the system in a programming language model. Each programming language creates a different model. There is, for example, a C++ machine. This particular language model is created through a very large library of runtime support services. There is a distinctly different model created by the Java runtime environment. We do not concern ourselves with this low-level implementation detail until we actually begin to map our high-level design model onto a particular language runtime environment. The module specification is simply a low-level partition of the system functionality. The three central issues that emerge from the module description are the structure of the system, the precise specification of data structures, and the data flow from one module to another. There must be, however, a one-to-one mapping between module specifications and code modules. Each module specification will result in exactly one code module. There will be no code modules that do not have design module specifications.
