A process model is a conceptual representation of the phases of a process. Such a conceptualization highlights some aspects (and evidently hides others) of the whole process by

• drawing lines of demarcation into the otherwise monolithic phenomenon
  • thus assigning clear steps and deliverables to the phases and
  • creating a viewpoint that provides clarity for everyone involved

Some problems become easier to solve by this highlighting (and hiding), others may even get more complicated because of it. Choosing the right process model for the given problem is an important professional decision.

Classification

• Linear process models – phases that happen sequentially, one after another
• Iterative process models – phases that are repeated in cycles
• Parallel process models – activities that occur concurrently

Cookbook metaphor

Alberta proposes the following metaphor. Most of the time the processes of software development are more like authoring a cookbook than following a specific recipe. It is not just following a set of steps to get the well defined result for certain. It requires continuous evaluation and decision making while moving through each phase of a given project. This continues well past the initial development project.

By this metaphor process models are not to be followed blindly, step by step. Rather they give specific, empirical and professional viewpoints and ways of thinking about the solution of a problem.