What is PERT in Project Management?

Did you know that the PERT chart was first used by the U.S. Navy in 1957 during the Polaris missile project? Today, it is considered as one of the foundational concepts of project management, right alongside Gantt charts and the Critical Path Analysis methods. If you are unsure of the project activity duration and have a complex project at hand, the invaluable PERT chart is for you.

In this guide, we will deep dive so as to understand what this concept entails, how you can use it, and what its top features and limitations include. Let's jump right in, starting with the basics:

"What is PERT in Project Management?"

Simply put, PERT is an acronym that stands for Project (or Program) Evaluation and Review Technique. This project management tool helps project managers?in a variety of ways:

  • Offers a graphical representation of a project's timeline by using circles or rectangles called nodes, directional arrows, and divergent arrows?

Note: The directional arrows signify activities and the nodes represent the milestones.

  • Represents tasks via these nodes that are linked by vectors or lines
  • Helps break down the individual tasks of a project for more in-depth analysis and understand the critical path that includes the minimum time required for project completion
  • Allows managers to evaluate the time estimates based on three segments – optimistic, most likely, and pessimistic – and gauge the resources that are required to monitor and manage a project
  • Helps engage in effective project scheduling, identify resources needed to finish the project, and create a realistic project budget

Note: Typically, project managers prefer PERT charts over Gantt charts as they help identify task dependencies that need to be performed in a specific manner. However, remember that the former is more challenging to interpret.

Moving on, it is time to understand how you can calculate a PERT chart.

How to Calculate a PERT Chart?

In this section, we will understand how to calculate your project duration using the Program Evaluation and Review Technique.

As mentioned earlier, a PERT chart depends on three key factors:?

  • Optimistic (O) Time: This is the shortest amount of time required to complete a task/ activity.
  • Pessimistic (P) Time: It signifies the longest time it will take to complete a task/activity. You can think of it as analyzing the possible worst-case scenarios.
  • Most Likely (M) Time: This entails identifying a reasonable estimate of the best-case scenario and understanding how long it will take to complete the required tasks or activities, assuming that there are no delays.

Note: You can also factor in the Expected Time, which is essentially the best and most realistic estimate of how long it will take to complete the task or activity, with the assumption that there will be issues or obstacles to overcome. Once you have the data for P, O, and M values at hand, you can use the PERT chart formula to calculate the expected duration of a task:

(O + (4*M) + P) / 6

Next, let's deep dive to understand how you can create a foolproof PERT chart.

How to Create a PERT Chart: A Step-by-Step Lowdown

By now, you might have understood that a PERT chart is a must-have for project managers in the planning phase of the project. Here are the steps to create a PERT chart:

Step 1: Start by identifying the project milestones and break them into individual tasks.

Step 2: Next, understand the task sequence as well as their dependencies. These are depicted using directional arrows. This will help your team to understand the sequence they need to embrace to tackle each task logically.

Step 3: Make the PERT diagram by taking the events and milestones (numbered nodes) you identified in the previous steps. Then, you'll need to outline the tasks and activities that your team members must accomplish between each node, using directional arrows or divergent arrows.

Step 4: Calculate the expected time a task will take and do an estimate for each task. The end goal is to set a realistic timeframe.

Step 5: Next, you'll need to figure out the critical path and identify any possible roadblocks. There you go. Your PERT chart is ready.

Pro tip: Make sure to constantly revisit and review your PERT chart and make the necessary changes as the project advances. Your PERT chart is an ever-evolving network diagram that needs consistent and real-time reviewing.

In the following section, we will go over the advantages of using a PERT chart.

Five Advantages of PERT Chart in Project Management

In this section, we will look at the top five advantages of using a PERT chart:

  1. Simplifies overly complex projects where the time duration is unpredictable by allowing managers to easily visualize the task dependencies between each step in the process
  2. Facilitates strong collaboration between departments as data is needed from multiple departments and offers visibility into the responsibilities for every team member involved
  3. Allows for better alignment of the overall strategic goals of the organization?
  4. Allows project managers to create flexible what-if scenarios and save precious time by mapping out the tasks, time, and resources for a project
  5. Allows managers to track the required assets throughout the project lifecycle Now that you have understood some of the advantages of using PERT in a project, let's look at some of its limitations.

Limitations of a PERT Chart

  • PERT charts are heavily dependent on data. Hence, data quality and relevancy are important for accurate, reasonable, and effective results.
  • The resource who is conducting the PERT analysis should have extensive experience in the process. Plus, its use is highly subjective.
  • PERT charts are labour-intensive and, by extension, time-intensive as the data needs to be constantly reviewed and analyzed.
  • In order for the chart to be useful and accurate, you'll need to continuously review and update it.
  • These charts do not take into account the financial positioning of a project as they are deadline focused.

To make things easier and reduce the workload, project managers often make use of robust PERT chart software. This all-purpose tool aids in estimating a more realistic duration of the project.?

Closing Thoughts

You can think of PERT charts as a visual representation of a series of tasks/events that must transpire within the project scope. This is why leveraging a dedicated PERT chart maker makes sense, as it empowers project managers to create dynamic PERT charts and deliver real-time results.

So if you wish to organize and schedule tasks, and set milestones seamlessly and easily as you move from one phase to another, the right time to get your hands on this holistic, results-driven tool was yesterday.