What are PERT charts and how to create them.

A successful campaign balances the combination of several factors, such as cross-functional teams, tight deadlines, and intricate dependencies. For marketing leaders, navigating this complexity to ensure on-time, on-budget delivery is a primary challenge. However, simply moving faster isn't enough; you need a strategic tool for gaining clarity, mitigating risk, and achieving predictable success.

One such tool is known as a program evaluation review technique (PERT) chart. PERT charts can help determine timelines, establish priorities, and identify potential roadblocks. This article serves as a practical guide for understanding and constructing 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
Visualizing a path forward

A PERT chart provides a map of a project as a network diagram. A node (such as a circle or rectangle) in the diagram represents each task associated with the project. Nodes connect with arrows indicating the order of tasks and task dependencies.

A completed PERT chart allows the entire project’s visualization, including time estimates for each task and which tasks to complete first. Teams can see potential bottlenecks and identify a critical path (the dependent task chain estimated to take the longest total time).

Typically, teams create a PERT chart before a project begins to gauge its full scope, identify potential issues, and map out an appropriate timeline. This chart contrasts with another project planning tool, the Gantt chart, which organizations primarily use to monitor project progress. PERT charts also provide insights that Gantt charts often do not, including creating a clearer depiction of task hierarchies and interdependencies, and estimating the entire timeline and variability.

One of the unique features of a PERT chart is its ability to deal with uncertainty. Rather than relying on a single deadline, PERT charts use a weighted average of four different time scenarios to calculate a realistic expected time.

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

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

Additionally, you can calculate the variance as (P-O)/6 to estimate how much the actual time may deviate from the expected time.

PERT chart vs. Gantt chart

While both are essential, they serve different phases of the project lifecycle:

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

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

1. Identify milestones and project tasks.

Breaking the project down in the project planning stage is the first step. Start with the final deliverable and work backward to identify every major milestone and the constituent tasks required to achieve them. Connecting with all project stakeholders is valuable to set expectations, align on goals, and discuss what the overall project outcome should be.

2. Determine task dependencies.

Task dependencies are tasks that rely on another task to be completed. Identify which tasks must happen in sequence, and which can happen in isolation. Examples include content teams reviewing personalized net new content to make sure the content aligns with brand standards and legal compliance. Task dependencies can be used in work breakdown structures. PERT charts visualize the dependencies that exist in each task to provide a visual example of relationships between tasks.

3. Estimate project time frames.

Apply the expected time formula to each task. It’s important to consult teams who contribute to a task on what their expected timelines are. Once you connect with teams who will carry out work, make sure to share expected time frames with executive leaders to ensure project execution alignment. Teams can also use the critical path method (CPM), which identifies key activities in a process and evaluates the time required to complete those key activities.

4. Translate your tasks and milestones into nodes.

Begin creating the chart by arranging each task and milestone on a large diagram. Nodes should represent these tasks. Note that as you begin the next step, you may need to move the nodes around, so sketching things out on a whiteboard or on a computer program will make this easier.

5. Draw vectors between tasks.

Using your notes on task prerequisites and interdependencies, draw arrows between your nodes to indicate which tasks form dependent chains. Keep in mind that you can have parallel chains if some tasks do not affect others. You may also want to include time estimates on the nodes or the arrows connecting the nodes so that you can later estimate the entire project time.

6. Analyze and optimize task progress.

Once drawn, calculate the total time for each path. Identify the critical path (the longest time). Look for opportunities to break up long tasks or move resources to parallel workflows to optimize the schedule. Examples could be a team identifying teams that are bottlenecks, preventing task progress. Simplifying the number of steps within a project and limiting the number of teams that contribute can help prevent projects from stalling.

Why invest the time to build this diagram? PERT charts provide insights that standard lists miss, specifically regarding efficiency and risk management.

• Clarify critical paths: It identifies the longest chain of dependent tasks. If any task on the critical path is delayed, the whole project is delayed. Knowing this allows managers to prioritize these specific tasks.
• Reveal parallel workflows: You can easily see which tasks are independent of one another. If you have the resources, these tasks can be done simultaneously (in parallel) to shorten 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 allows for proactive risk management.
• Coordinate departments: By visualizing 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 juggle responsibilities ranging from stakeholder communication to crisis management. Adding the PERT chart to your toolkit allows you to plan with confidence, turning complex chaos into a structured, visual, and achievable plan. Adobe Workfront can help you juggle many responsibilities as you plan and organize projects of varying complexity and scale. Having the right tools and knowing how and when to use them is vital. We hope the information in this article proves helpful 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.