Chapter 4. The Process Model
The composite chart of Figure 3.1 is repeated in Figure 4.1 with the process model highlighted. As we summarized in the last chapter, and can see from Figure 4.1, this model consists of data flow diagrams and process specifications. Its purpose is to specify the information processing requirements of the system.
4.1 Data Context Diagrams
Context diagrams are just special cases of data and control flow diagrams, but they serve such a special and important role in the model that they merit special attention. They identify the external entities (typically, other systems, ...