What are PERT charts and how to create them

Running a successful campaign means managing cross-functional teams, tight deadlines, and complex dependencies all at once. For marketing leaders, keeping delivery on time and on budget amid this complexity is a real challenge. But moving faster alone won’t cut it — you need a strategic tool that brings clarity, reduces risk, and drives consistent results.

One such tool is the program evaluation review technique (PERT) chart. PERT charts help determine timelines, set priorities, and flag potential roadblocks. This article is a practical guide to understanding and building PERT charts in project management.

This post will cover:

Key components of PERT charts
The four time estimates of PERT
How to create a PERT chart: A six-step process
Benefits of using PERT charts
Visualising a path forward

A PERT chart maps out a project as a network diagram. Each task is represented by a node — typically a circle or rectangle — and nodes are linked by arrows showing the order of tasks and their dependencies.

Once complete, a PERT chart gives your team a full view of the project — including time estimates for each task and the order in which they should be completed. Teams can spot potential bottlenecks and identify the critical path: the chain of dependent tasks estimated to take the longest total time.

Teams typically create a PERT chart before a project kicks off, using it to gauge the full scope, identify potential issues, and map out a realistic timeline. This sets it apart from the Gantt chart — another project planning tool used primarily to track progress during a project. PERT charts also offer visibility that Gantt charts often don’t, providing a clearer picture of task hierarchies, interdependencies, and overall timeline variability.

What sets PERT charts apart is how they handle uncertainty. Instead of locking in a single deadline, PERT charts calculate a realistic expected time using a weighted average across four different time scenarios.

When using a PERT chart, there are four types of timelines:

Expected time = (O + 4M + P)/6

You can also calculate variance as (P-O)/6 to estimate how much the actual time may differ from the expected time.

PERT chart vs. Gantt chart

Both are valuable, but they serve different phases of the project lifecycle:

• PERT charts are typically created before a project begins. They’re used for planning, estimating time, and mapping out dependencies.
• Gantt charts are primarily used during a project. They focus on scheduling, resource allocation, and tracking progress against specific dates.

Ready to map out your project? Follow these steps to build an effective PERT chart.

1. Identify milestones and project tasks.

The first step is breaking down the project during the project planning stage. Start with the final deliverable and work backwards to identify every major milestone and the tasks needed to achieve them. Engaging all project stakeholders early is key to setting expectations, aligning on goals, and agreeing on the overall project outcome.

2. Determine task dependencies.

Task dependencies are tasks that can’t begin until another task is complete. Identify which tasks must happen in sequence and which can run independently. For example, content teams may review personalised net new content to ensure it meets brand standards and legal compliance requirements. Task dependencies can also be incorporated into work breakdown structures. PERT charts map out these dependencies to show how tasks relate to one another.

3. Estimate project time frames.

Apply the expected time formula to each task. Consult the teams contributing to each task to understand their expected timelines. Once you’ve engaged the relevant teams, share those time frames with executive leaders to align on project execution. Teams can also use the critical path method (CPM), which identifies key activities in a process and assesses the time needed to complete them.

4. Translate your tasks and milestones into nodes.

Start building the chart by placing each task and milestone on a large diagram, using nodes to represent each task. Keep in mind that you may need to reposition the nodes as you work through the next step, so sketching the layout on a whiteboard or in a computer program first will make this much easier.

5. Draw vectors between tasks.

Using your notes on task prerequisites and interdependencies, draw arrows between your nodes to show which tasks form dependent chains. Bear in mind that parallel chains are possible where some tasks don’t affect others. Adding time estimates to the nodes or the connecting arrows will also help you calculate the total project timeline further down the track.

6. Analyse and optimise task progress.

Once the diagram is complete, calculate the total time for each path and identify the critical path — the longest one. Look for opportunities to break up lengthy tasks or shift resources to parallel workflows to optimise the schedule. For example, teams might spot bottlenecks that are slowing task progress. Reducing the number of steps within a project and limiting the number of contributing teams can help keep projects on track.

Why invest the time to build this diagram? PERT charts surface insights that standard lists miss — particularly around efficiency and risk management.

• Clarify critical paths: A PERT chart identifies the longest chain of dependent tasks. Any delay to a task on the critical path delays the whole project — knowing this allows managers to prioritise those specific tasks.
• Reveal parallel workflows: It’s easy to see which tasks are independent of one another. With the right resources, these tasks can run simultaneously — shortening the overall project timeline.
• Enable ‘what-if’ analysis: Once mapped, you can test different scenarios. What if the supply chain is delayed? What if we add more staff to Task C? This supports proactive risk management.
• Coordinate departments: By visualising dependencies, different teams (for example, Dev and QA) understand why their deadlines matter to the larger picture, fostering better collaboration.

As a project manager, you’re constantly balancing responsibilities — from stakeholder communication to crisis management. Adding the PERT chart to your toolkit lets you plan with confidence, turning complex chaos into a structured, visual, and achievable plan. Adobe Workfront can help you manage these responsibilities as you plan and organise projects of varying complexity and scale. Having the right tools and knowing how and when to use them is essential. We hope the information in this article helps as you expand your project management toolbox to include PERT charts.

Take a Workfront product tour to see how our software makes building PERT charts simple and intuitive.