Here are the characteristics of the waterfall model:
- The project consists of sequential, non-overlapping phases, where a phase cannot begin until the previous phase is already completed.
- At the end of every phase, there is a gate where a decision is made to allow the project to move forward or not (Stage Gate)
- Changes are controlled. Major changes are only allowed if the CCB (Change Control Board) approves them.
- The product is only finished at the end of the last phase.
- Once the project is done, the product/service enters into a maintenance phase.
- Low overhead of the methodology compared to other methodologies (such as Agile).
Note: The last point is debatable.