
188 CHAPTER 7 Design: Architecture and Methodology
entities. In Figure 7.10, the design focuses on potential reuse of the three
functions. The Add, Modify, and Delete functions are grouped under data-
base common services for potential reuse and multiple usages. In design, we
should not only be concerned with the actual structures but also ask which
one is the preferred alternative. Note that in Figure 7.9, the individual enti-
ties and their functions serve a single purpose and individually appear very
cohesive, while in Figure 7.10 the database common services serve multiple
purposes and provide some reuse. However, with common services for
reuse, ...