Software Engineering for Students A Programming Approach

Exercises 119
During the second stage of data flow design, the data flow diagram is transformed
into a structure chart, showing the constituent components of the software and
their interrelationships, by:
1. identifying the most important or central transformation in the data flow diagram
2. lifting this transformation into the air, leaving the others dangling beneath it.
This creates a hierarchical or tree-shaped structure for the software.
Arguably data flow design leads to the most modular structure for the software, since
the design is based on “data coupling” (the best type) between the components.
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Exercises
9.1 Complete the development of the patient monitoring system described in this chapter.
9.2 Apply data flow design to devising an architectural structure for each of the systems
described in Appendix A.
9.3 What characteristics should a good software design method possess? Does data flow
design exhibit them?
9.4 Suggest the facilities of a software tool that could assist in using data flow design.
9.5 Compare and contrast the principles behind the following design methods:
■ functional decomposition
■ data structure design
■ data flow design
■ object-oriented design.
9.6 Evaluate data flow design under the following headings:
■ special features and strengths.
■ weaknesses
■ philosophy/perspective?
■ systematic?
■ appropriate applications
■ inappropriate applications
■ is the method top-down, bottom-up or something else?