Critical Path Method ThumanCo, Project Management, Angela Thurman

Pitfalls When Using the Critical Path Method (CPM)

The Critical Path Method (CPM) is a project modeling and scheduling technique for large or complex projects.

A core benefit of CPM is that it helps project managers stay on task and under budget by identifying individual tasks and their interrelated dependencies. Understanding these dependencies helps identify the anticipated time to begin and complete each task within the project. This effectively allows accurate schedule prediction when projects comprise hundreds of tasks.

The method gets its name from identifying the critical path: the longest stretch of tasks with interrelated dependencies. The critical path is the sequence of related tasks that take the longest to complete.

Even reliable project management methods have pitfalls

While CPM is a valuable project management technique, several pitfalls can occur during its execution. Project managers must be aware of these potential pitfalls and proactively work to mitigate any adverse impacts.

Here are some of the common pitfalls encountered when using CPM:

Inaccurate estimates

As the name implies, CPM relies on identifying the critical path to estimate project delivery dates. Inaccurate estimates lead to schedule delays and cost overruns.

Ignoring resource constraints

Failing to consider resource availability and limitations can result in resource overallocation or underutilization, leading to delays and inefficiencies. The challenges occur when a schedule is finely tuned to tasks identified on the critical path, those tasks run late, and the assigned resources have been allocated to new projects based on the previously projected ending date.

Failure to account for risk

CPM assumes that everything will go according to plan. Unfortunately, this is not always the case in real-world projects. Not anticipating, identifying, and mitigating project risks can result in disruptions, delays, and cost overruns.

Over-reliance on the critical path

While the critical path is essential in meeting projected schedules, focusing solely on it can lead to neglecting other important tasks influencing the project’s success. 

Another way of looking at this is the pitfall of limited focus on non-critical-path tasks. Not giving adequate attention to non-critical-path tasks may result in missed optimization or improvement opportunities.


Successful CPM implementation requires strict adherence to the project plan and its carefully orchestrated schedule. While this is crucial, it can also lead to inflexibility in the face of unexpected issues, making accommodating changes in project scope or priorities challenging.    

Unrealistic expectations

With its emphasis on identifying the critical path tasks, the CPM methodology may set unrealistic expectations regarding project timelines and deliverables. This can lead to disappointment and dissatisfaction among stakeholders.

Overcomplicated scheduling

With the focus on closely coupling tasks through completion dates to arrive at the critical path, CPM schedules can become overly complicated and difficult to understand, leading to confusion and errors.


Understanding the potential pitfalls is critical in applying CPM as it helps project managers stay on track when defining project scope, allocating resources, and making adjustments as the project rolls out. By considering these issues from the beginning, project managers can help ensure that critical activities are aligned with expectations, leading to a successful project outcome.

At Thurman Co., we embrace best practices and proven methodologies as part of the foundational framework driving how we operate and interact with clients, suppliers, and partners.

We help businesses manage projects to significantly impact their success and growth. When you’re ready to put your project in the hands of a trusted professional organization, contact us to learn more about working together.

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