ABSTRACT
The simplistic model of the waterfall approach has pretty much drawn fire since people first discussed it (see Figure 6.1). It is easy to see why-it is simply unrealistic.
A more sophisticated version of the waterfall approach uses a model with loop backs for the cases where a stage gate in the model cannot be passed and the team must cycle through that phase again. This version of the waterfall approach is more realistic than the simplistic model but it still has flaws; for example:
The long-term prescient schedule is still part of the system, although it may be perturbed by unplanned phase iterations.
