5 Project Management Methodologies and Their Risks: Part 1 – Waterfall

Martin Večeřa

While we hear a lot about agile, waterfall project management is still very common these days. Why is it so popular? What are the risks of sticking to it? Are there any at all?

We would like to welcome you to our series about project management methodologies. There are 3 parts in total (Traditional methods – i.e. Waterfall, Agile and Lean).

There are plenty of articles that explain technical details of various Project Management Methodologies when you search for them. To provide some additional value, we would like to concentrate more on the human aspect of using these methodologies, how they can influence the communication and overall progress and results. We will put some psychology into it.

For a subtle technical introduction, let’s begin with looking around what has been already defined and whether there isn’t any standardization authority. In Project Management, this could be the Project Management Institute (PMI). Their mission is to be the leading not-for-profit professional membership association for the project management profession. 

Founded in 1969, PMI delivers value for more than 2.9 million professionals working in nearly every country in the world through global advocacy, collaboration, education and research.


PMI regularly releases the PMBOK which is a guide detailing a set of standards that characterize project management.

PMBOK stands for the Project Management Body of Knowledge. It summarizes the five process groups that are prevalent in almost every project. They are:

  1. Initiating: Defining the start of a new project or a new phase of an existing project.
  2. Planning: What is the scope of the project, what are the objectives, and how the objectives will be achieved.
  3. Executing: Actually doing the work defined in the project management plan.
  4. Monitoring and Controlling: When you need to track, review, and regulate the progress and performance.
  5. Closing: Concluding all activities across all Process Groups to formally close the project or phase.

Along with this, it includes best practices, conventions, and techniques that are considered to be the industry standard. Latest edition (the sixth) was released both online and in print in 2017. We definitely recommend it as a great resource if you are into a career path in Project Management for instance.

We will soon see that these project phases are more or less reflected in all frequently used methodologies.

In this first part of our series, we inspect the most traditional project management methodology.

Methodology 1: Waterfall Project Management

Waterfall project management is a linear sequential approach where one phase can only begin when the previous phase is completed. 

Also, you need to have the final results (product requirements) specified in advance. That puts a high demand on mental skills and responsibility of all participating teams to think everything through and imagine all possible risks in advance.

Risk 1. Unfortunately, to think about the future is not what humans are especially good at. Also, we are often overly optimistic about the future and the project progress.

Waterfall is a heavily documentation-oriented project management. Originally, its aim was to allow a smooth transition of knowledge between individual team members as they come and go. Simply, a new team members reads the existing documents and they can smoothly onboard. In theory of course.

Risk 2. This does not necessarily reflect reality as the documentation is written by the team members who are very well familiar with the project, which leads to omitting details here and there.

The core principle of the Waterfall project management methodology is to have a clear definition of outcomes of individual phases and acceptance criteria of the next phase. Individual phases are executed by teams of specific experts.

Risk 3. When there is an overlap of people between individual phases, it can become very hard for them to stick to the rules of phases handover. This can create unwanted unpredicted states.

Risk 4. Waterfall typically flows only down. There can be a reverse speed in your gearbox. When a critical issue is discovered, the only thing that can be done is to return to the previous state of the process. This causes lengthy delays and problems with teams utilization. 

Risk 5. In Waterfall project management, the active phase indicates which team is the busiest one at the moment. The team in the earlier phase has completed their work and they could have started on another project already. The team in a later phase might be still completing their previous project. Do you see the big hidden assumption here? The assumption is that all phases take equal amount of time. This is rarely true.

This constant inflow of other projects (to keep the people utilized) makes reversing the process very difficult. Suddenly, one team faces a situation where there are two projects on their plate at the same time. On the other hand, the team that returned the Material or Work In Progress (WIP) to the previous phase is empty-handed.

Risk 6. The WIP handover between the phases is a typical friction point between the teams. When team members are under stress and the project deadline is close, even a tiny issue can fire up a huge blame war. It is important to remind the teams that they are all in the same boat and that they have the same goal.

Risk 7. The level of customer involvement in Waterfall project management is very low. The customer does not participate in the work on the project. They are able to see the final product only when it gets finished.


Who can benefit best from the Waterfall project management? So far we mostly talked about the risks in the Waterfall methodology. Yet, there are some really good cases when it should be strongly considered.

If you have a manufacturing process that is spread over several geographical locations and there is not an option to return WIP back to the previous stage, then it is great to have the handover criteria set very well.

Other indicators can be a manufacturing process with years of experience (you produce the same thing for years already) with no to only cosmetic changes. When the WIP stays for a significant amount of time in each phase and you have a constant throughput, then Waterfall is probably your friend.

Also the right tool with support for tracking multiple projects at the same time can be a huge help.

Next time, we’ll have a look on Agile and derived methodologies – Scrum and Kanban.