In a waterfall project model, every phase requires completion before a new phase can start. Such a model type is essentially utilized for projects which are smaller and do not entail any uncertain requirements. As each phase ends, a review is undertaken to understand whether the project is moving on track or whether it needs to be continued or discarded. Waterfall project methods basically focus on quality.
While the waterfall project method has its set of advantages, it also has certain weaknesses, which are discussed below.
1.) Working model is fixed
It might be difficult to adopt the waterfall project method when there is uncertainty regarding the client’s requirements. In other words, it does not suit in volatile environments. When the ultimate goals of the project are left undefined in the early stages of project conceptualization and have the potential to change as the project proceeds, it would not be possible to follow a waterfall project method.
2.) Shared dependency
Waterfall project models follow a sequence-based approach, which might not be suitable for all projects. In fact, it could work against some projects. For example, when any modifications are made in an earlier stage, it could cause disruption in the stages that follow. This is because there is shared dependency existing among the different stages, which makes it difficult to introduce change at any point during project execution.
3.) Result related clarity
Waterfall project models are typically designed around the project results. But there are some projects in which there is no clarity (in the earlier stages) with regard to the results that need to be delivered or the ultimate goals that have to be met. Again, such a scenario would not allow the use of a waterfall project method because in the absence of a detailed product definition and technology, the approach definitely fails.
4.) Correction of errors
In waterfall projects, it becomes very difficult to go back to a stage and make changes or corrections. For example, if you consider a software-related project, when it is already in the final testing stage, it is very hard to go back and make corrections or changes in its source code (maybe due to improper planning in the initial stages).
5.) Delayed results
In the waterfall project method, the results might not come through till the very end when the project is almost ending. This means that it might be hard to assess whether the project is going in the right direction or not.