What is a PERT chart? Easy steps to create and use one

If you’ve ever struggled with mapping project tasks or keeping track of dependencies, we have the perfect solution for you. 

A PERT chart, also known as a PERT diagram, is a tool used to schedule, organize, and map out tasks within a project.

PERT stands for program evaluation and review technique. It provides a visual representation of a project's timeline and breaks down individual tasks. These charts are similar to Gantt charts, but structured differently. 

This diagram consists of a few steps to get you from a project start date to end date. In this article, we’ll cover the five steps, show you an example, and explain how to effectively use a PERT chart to your advantage. 

How a PERT chart works

A PERT chart works by visually representing a project’s tasks and the dependencies connected to each one. You might use one to create an initial project schedule and estimated timeline to share with project stakeholders before the project actually begins.

Creating a project roadmap such as a PERT chart can help you accomplish several project planning activities, including:

• Getting schedule and timeline signoff from leadership

• Communicating project objectives to stakeholders

• Visually mapping out a complex project and its interdependencies

• Estimating the time needed to complete individual tasks 

In order to make the most of your PERT chart, you should first understand the steps needed to complete one and how to visually map out your diagram.

How to make a PERT chart

If you want to stay ahead of deadlines, creating a PERT chart is the way to go. This guide will walk you through how to create a PERT chart step-by-step, so you can visualize every task, dependency, and deadline with ease.

1. Identify project tasks

The first step in creating a PERT chart is the project planning stage, where you define the key project tasks that will shape your timeline. Before mapping out task dependencies, take time to gather essential details such as:

• A business case

• A communication plan

• An initial kickoff meeting

Laying this groundwork early ensures you’re prepared to connect dependent tasks and establish a clear project scope before moving forward.

2. Define task dependencies 

A task dependency is a task or milestone that relies on another task to be completed before the task at hand can be started. Dependent tasks are a core part of the PERT method, often referred to as a logical relationship, and are commonly used in a work breakdown structure. 

Creating dependencies can help you properly track work, ensure tasks are completed, and establish clear communication—especially for complex projects. Without well-defined dependencies, it’s difficult to plan timelines and estimate overall project duration.

A PERT diagram visualizes dependencies by connecting and numbering tasks. While not as detailed as a work breakdown structure, it provides a clear overview of task relationships and required work.

3. Connect project tasks

With task dependencies established, start creating your PERT chart by connecting project tasks to one another. These connections consist of arrows, which represent tasks, and nodes, which represent events or milestones.

For example, place parent events within your nodes (represented as numbered circles or squares) and draw task arrows to represent the dependencies needed to complete your events. 

This network diagram layout offers a simple structure that is straightforward for project stakeholders to understand.

4. Estimate project time frame

Now it’s time to estimate your overall project time frame using the critical path method (CPM) and the PERT equation. The critical path is the longest sequence of tasks that must be completed to successfully finish an entire project. 

The goal is to find the longest task sequence to estimate the shortest possible project duration. Time estimates in PERT analysis are based on:

• Optimistic time: The minimum amount of time needed to accomplish a task.

• Pessimistic time: The maximum amount of time needed to accomplish a task. 

• Most likely time: The best estimate of how long a task will take.

Using the PERT calculation, you can estimate task duration and completion time with the PERT formula:

Expected Time = (O + (4 × M) + P) ÷ 6

This can be measured in minutes, hours, days, or even weeks. 

Pert calculation example:

For instance, if a task has an optimistic time of 30 minutes, a pessimistic time of 60 minutes, and a most likely time of 45 minutes, the calculation would be:

(30min + (4 × 45min) + 60min) ÷ 6 = 45 minutes. 

Once you’ve completed the PERT estimate for each task, total them along the critical path to find the overall project timeline.

5. Manage task progress

The final step in creating a PERT chart is managing progress until project completion. This involves tracking task dependencies, resolving bottlenecks, and ensuring all project milestones are met.

A PERT chart in project management should be updated in real time as changes occur. Pairing it with a change control process can help track modifications and maintain clear communication.

Once all tasks are complete, archive project materials in a shared space for easy access to past PERT analysis examples.

PERT chart example

Now that you understand how to make a PERT chart, it’s time to create one of your own. Since every project varies in complexity and time frame, your PERT diagram may look slightly different. However, the core structure remains the same.

To start, follow these steps:

• Drawing your numbered nodes: These represent the major project events, also known as parent tasks. When completed, these nodes will collectively form the full project. Your PERT diagram example might contain any number of tasks, but 10 is a good starting point. 

• Connect your nodes to tasks: Use arrows to illustrate task dependencies. These tasks must be completed to move forward with each milestone. While your PERT example should have a defined beginning and end, the middle can become more complex as dependencies branch out. 

PERT chart example with solution

Here’s a PERT example with solution to give you a clearer picture of how these elements come together. Suppose you're managing a website launch:

What should a PERT chart template include?

A PERT chart template typically includes several key elements to help structure and visualize project activities. Here’s a breakdown of common terminology and their definitions:

• Nodes: Nodes represent project events—the major components that make up your entire project. For example, in a website design project, a node might represent a new logo design.

• Tasks: Tasks are the specific actions required to complete a node. For instance, if a node represents a new logo design, a task might involve creating three different logo mockups.

• Dependencies: Task dependencies indicate relationships between tasks, meaning one task must be completed before another can begin. For example, a landing page cannot go live until the copy is written and approved.

• Dependencies without resources: Some dependencies exist without a direct task connection. For instance, while a product launch and a landing page may be related, they don’t necessarily share a specific dependent task.

What’s the easiest way to build a PERT chart template? Use a project management tool. It helps you map out task dependencies, keep an eye on the project timeline, and spot bottlenecks before they slow you down.

You can also pair your PERT chart template with visual tools like Lucidchart. These apps let your team members collaborate in real-time, tweak the project schedule on the fly, and keep everything on track for project completion—all in one place.

When to use a PERT Chart

Project managers use PERT charts to evaluate and complete a given project. But with so many other methods to choose from, how does a PERT diagram compare? 

For starters, a PERT chart is a good method when you’re looking to evaluate the timeline, resources needed, and a project’s critical path. Let’s look at each of these a little closer.

• To determine the critical path: One of the key features of a PERT chart that sets it apart from other methods is its ability to determine a project’s critical path. This is important when visualizing the overall timeline of a project. 

• To evaluate resources: With the unique features a PERT chart offers, you can easily display which tasks require resources and which don’t. This saves both you and project stakeholders time by having that information upfront and accessible. 

• To estimate time: Since a PERT chart evaluates both individual task duration and overall project duration, it’s a great tool when you need to understand the expected timeline during the initial project planning phase.

Overall, creating a PERT chart is a good option for a simple project plan that can easily be shared with team members. Use this chart to quickly share resources and timelines.

PERT chart vs. Gantt chart

PERT charts and Gantt charts are often confused, though they have a few key differences. Not only do they differ in their visual appearance, but they also provide different features depending on what your team needs. 

Here are a few key features to note when deciding on which one is right for you:

1. PERT charts are flowcharts while Gantt charts are bar graphs: One of the biggest differences is their visual layout. While Gantt charts take on a traditional bar chart approach, PERT charts are less structured in appearance and take on different layouts depending on the project.

2. Gantt charts offer organization while PERT charts offer customization: Gantt charts are more structurally organized. On the other hand, PERT charts allow simple layout customization which is better for high-level project needs. 

3. PERT charts can be used before the project begins: Since PERT charts offer a simple project plan and timeline layout, they’re often used as visual guides during the project kickoff. Project managers then use another method, like a work breakdown structure or Gantt chart, to specifically map project tasks and dependencies. 

In general, Gantt charts are more popular for mapping out project activities and tasks throughout the project lifecycle while PERT charts are popular for time mapping in the initial project stages. They can be used separately or together to create a comprehensive plan.

Plan ahead with a PERT chart

By implementing a PERT diagram of your own, you can be sure your next project is planned accurately and correctly. With a simple layout and timeline estimates, your team will have clear direction on project tasks and be prepared for whatever comes their way. 

If you’re looking to take your next project one step further, try Timeline with Asana for project tracking capabilities.

FAQs about PERT meaning and how it works