You are a senior systems analyst at Digital Consulting, a growing IT consulting firm. You are leading the development team for a major client. You need to explain structured analysis to your two newly hired junior analysts (Sara and Mike) before meeting with the client tomorrow afternoon.
1. Describe the rules for creating a context diagram.
2. Make a basic list of dos and don’ts when developing DFDs.
3. Explain the importance of leveling and balancing.
4. Ask Sara and Mike to review the order system context diagram on page 208, and compare it with the order system diagram 0 DFD on page 212. Then ask them to answer the following questions:
(a) How many external entities are shown in each diagram?
(b) In each diagram, how many data flows connect to the external entities?
(c) How many sub-processes are identified in the diagram 0 DFD?
(d) Could the data store have been shown in the context diagram? Why or why not?