Rapid Development: Taming Wild Software Schedules

Spiral

At the other end of the sophistication scale from the code-and-fix model is the spiral model. The spiral model is a risk-oriented lifecycle model that breaks a software project up into miniprojects. Each miniproject addresses one or more major risks until all the major risks have been addressed. The concept of "risk" is broadly defined in this context, and it can refer to poorly understood requirements, poorly understood architecture, potential performance problems, problems in the underlying technology, and so on. After the major risks have all been addressed, the spiral model terminates as a waterfall lifecycle model would. Figure 7-4 on the next page illustrates the spiral model, which some people refer to affectionately as "the cinnamon ...