The Waterfall approach

The Waterfall model is a design process in which progress is seen as flowing steadily downwards (like a waterfall) through the phases.

The following diagram shows the typical representation of a Waterfall approach:

As you can see in the diagram, one phase does not start until the last one has finished. In the next section of this chapter, we'll talk about the phases of a Dynamics NAV implementation, which are presales, getting the requirements, analysis, development, deployment, and support. In our case, the analysis phase cannot start until all the requirements have been taken care of, and the development phase cannot start until all the requirements have been analyzed.

Companies have chosen this approach because it is the one that, theoretically, brings more certainty. Using this approach, the whole scope of the project is defined after getting the requirements, so it is easy to fix a cost for the project and fix an ending date. But, as we said, it is...