What is Critical Chain Project Management?

Last Updated October 11, 2023

Critical chain project management (CCPM) is based on the Theory of Constraints model developed by Dr. Eliyahu Goldratt to make manufacturing processes more efficient. It is used in project management as an alternative to typical task-based project structures.

CCPM does not focus on short-term milestones or set deadlines for each task. Rather, it asks people involved with a task to do it as fast as possible while retaining quality. The focus is on meeting an ambitious end goal.

It’s like the construction of a building. Those paying for the building have less concern about when the foundation is laid or when the building is wired. They are concerned about when it will be ready for them to move in.

Embracing Uncertainty

In a way, critical chain project management deals with the unknown in a project by embracing it.

By its very definition, a project is something new. Project managers cannot perfectly predict how a project will end before it even starts. CCPM takes this into account by focusing on the formation of estimates.

When project managers use CCPM, they first work on what is called focus time. This is an accurate estimate of when the project can be completed. Project managers should go into a project understanding that workers may over-estimate the time it will take to complete a task and may start late (the “student syndrome”) or finish early and continue to tinker with the final product of their task (this is called gold plating).

There also tends to be buffer time between tasks. In CCPM, the project manager takes out the extra time associated with tasks and the buffer time, then puts it into a “time bucket” called the project buffer. This time is used if needed.

Critical chain project management typically works best when a project team is not constrained by resources and can move forward as fast as possible. Those working on a task are left alone until they complete it – there’s no multitasking, gold plating or procrastination allowed.

Management Buy-In

For critical chain to be successful, management needs to both understand the process and approve of its use. Team members also must buy-in and understand the approach.

One way that can help both managers and team members visualize critical chain project management is the concept of a relay race. Runners in a relay race have the resources they need. The only constraint is the time it takes for them to run their section of the race before passing forward the baton. Similar to a relay race, every minute in a project is precious. Tasks should be completed early. If possible, the successor task can then start earlier. This can help speed up the entire project flow.

Addressing Potential Risks

As first formulated by Goldratt, the Theory of Constraints model identified the constraints that most frequently held up a project. The theory looks at any project as a series of links forming a chain and works to find the weakest link that can keep a project from reaching its completion. These links usually fall into one of five areas: process, person, machine, policy or procedure.

For CCPM, the most critical risk is that a task runs over the estimated time, creating a domino effect for each subsequent task. This is why project buffer time is built into every estimate.

Critical chain project management also must ensure that the needed resources are there for each critical task of a project – it’s the basis on which the entire theory is built. Resources must be available and not overcommitted to one task or segment of the project.

Villanova’s Project Management Capstone course teaches that the Theory of Constraints model has three rules that are used in critical chain project management:

identifying the key tasks
focusing on performance in those key tasks
subordinating all other tasks to the key tasks

Why This Is Important

Companies continue to recognize the need for effective project management but fail to deliver on expectations and costs.

The Project Management Institute’s (PMI) 2018 Pulse of the Profession® reported that 9.9% of every dollar is wasted due to poor project performance. Its 2019 Pulse of the Profession® noted an even higher percentage lost, reporting that 12% of project investment money is wasted due to poor performance.

The 2019 Pulse® report attributed this to three main causes:

Organizations do not bridge the gap between strategy design and delivery
Executives don’t recognize strategy is delivered through projects
The importance of project management as the driver of strategy is not fully integrated

While it might run against the grain of project management theories, Goldratt’s Theory of Constraints – which he explained in his book, “The Goal” – helps businesses focus on making changes where they are needed to reach business goals.

Critical chain project management takes this same approach to managing projects, offering businesses another way to approach eliminating constraints and raising the chances of projects being more efficient and successful.