Critical Path Method: How To Optimize Project Management

Creating a feature, ramping up a project or launching a new service is no small feat. In the process, project managers navigate a lot of moving, complicated parts. They need to understand what tasks to prioritize, how to complete them, and when to finish them.

The Critical Path Method (CPM) sets project managers up for success by identifying the most important sequence of tasks needed to complete a project.

What Is The Critical Path Method?

The Critical Path Method (CPM) is a project management technique, used to identify the sequence of tasks that take the longest time to finish in a project. The “critical” path is the longest path, including steps from start to end, that represents the minimum time required to complete a project.

The CPM enables project managers to prioritize tasks on the critical path to ensure they meet deadlines, identify parts that can quicken a project’s pace, and manage time effectively.

In general, CPM works best for projects with the following:

• Clearly defined tasks and jobs
• Activities that can be ordered
• Tasks that can be accomplished independently of each other

Critical Path Method Project Management

1. List Out Tasks and Activities

To start CPM project management, list out your project’s different phases, tasks, and subtasks. This could include steps to add new product features or materials needed for a marketing campaign. At this stage, aim for a high-level overview of what the project needs to succeed.

2. Figure Out Dependencies

Next, using the tasks, figure out how they relate to each other: What comes first, and what comes after? What tasks depend on other tasks? For example, when creating an app, finding the right software engineer precedes any code writing. This means that creating the app depends upon sourcing a developer.

You can use the following table as a template to make this process clearer. Note that tasks, at this point, do not need to fall in order.

Using the table, you can then map out unique pathways to help you identify the critical path for your project.

3. Write Out a Flowchart

Next, create a flowchart showing the chronological order of your identified tasks. You can do this using arrows and boxes in Google Slides or Microsoft PowerPoint. This helps you better picture the different paths leading to your project’s completion.

In reality, projects have multiple paths — some cross while others remain largely independent. Once you have everything figured out, your flowchart might look more complicated, like the Harvard Business Review’s example on building a house:

Source: Harvard Business Review

4. Calculate Times

After organizing your paths using a table and flowchart, figure out how long each task will take. This part requires some educated guessing. Based on what you know, how long will each task take to complete? How many days or weeks will you allocate for each one?

Collaborate with other teams to figure out their capacity; look at their workflow from previous projects; then, fill in your estimated durations on the table you made earlier.

5. Determine The Critical Path

Using your flowchart, add up each unique pathway’s duration. A path means moving from start to finish and going down with each arrow. Finishing one path does not mean completing the entire project. Instead, consider each path representative of different parts of a bigger project.

The one with the longest duration is your critical path, which determines the overall length of your project. Decreasing time spent on any step in this path will reduce the entire project’s timeline.

Calculating The Critical Path

To calculate the critical path, first add up the duration of each pathway. Whichever has the longest duration represents your project’s critical path.

Critical Path Method Examples

You can use the CPM outside of project management, even in party planning. Say someone wants to throw a party with a friend, and they want to do it efficiently. Using CPM, they start off with the following table:

This party features two clear objectives: baking cookies and setting up the dining area. Using the table as a guide, the planner then creates the following flowchart:

The flowchart lets the planner know they have two unique paths that lead to the finish. Using the numbers they estimated in the table above, the path on the right has a total duration of 240 minutes. The one on the left adds up to 775 minutes, which represents the planner’s critical path.

What does this mean for the planner? If they want to quicken the set-up process, they should look only at tasks involving baking. For instance, if the friend and planner agree to split the work, having the friend quickly set up tables does not reduce the time spent baking cookies, which represents the longer sequence.

CPMs can also optimize different processes found in the business world, such as ramping up SEO efforts. Say a recently hired managing editor of a blog creates the following table of tasks:

Here, the managing editor has two obvious paths: hiring writers and working with an SEO agency. Knowing this, they then create the following flow chart:

In this example, the paths collide — which is probable in an actual project. Still, you can easily determine the critical path by adding each one’s duration. The writing path has a duration of 13 days while the SEO path has a duration of 17 days — the latter is the critical path. To reduce the project’s total time, focus on reducing time spent on that pathway. This could include, for example, finding an SEO agency more quickly.

What did you think of this article? 

Give Feedback