What are PERT charts and how do they help with project management?

Project management is a complex process with a significant number of elements to monitor. Having a tool that helps streamline the work can make a big difference for the manager and team.

A PERT chart is one such project management tool that can help increase productivity. This chart, which represents the whole project, helps project managers create project schedules and timelines, and contains important information such as dependencies that can affect deadlines.

Let's take a closer look at PERT charts and how they can assist project managers.

A PERT (program evaluation review technique) chart is a diagram that maps and tracks project tasks and timelines. It allows project managers to visualize the timeline and task duration, and determine which dependencies could affect deadlines.

The chart shows a combination of squares or circles connected with arrows. Each shape represents a task and its allocated duration. This can help the project manager evaluate how fast a project can be completed and make sure everything is staying within scope.

A PERT chart breaks the project down into tasks and allows you to evaluate each activity and its effect on the milestones. By analyzing each task, you can streamline the project's timing and reevaluate dependencies between tasks.

Here are some key ways a PERT chart can help keep a project on track:

• Review the time allocated to tasks

• Evaluate the project timeline

• Make informed decisions about time management

• Maintain the project’s scope

• Find opportunities for process optimization and reduce bottlenecks

• Discover a critical path to completing a project

• Evaluate tasks and adjust their order

Implementing a PERT chart correctly allows you to create an optimized project schedule by sorting tasks based on priority. These charts are ideal for planning projects, especially when the timeline is vague and unclear.

The traditional PERT chart (activity-on-arrow diagram) has only two elements—nodes and arrows:

• Nodes (circles, rectangles, squares): these represent the project’s events or milestones.

• Arrows: these represent the tasks needed to achieve the milestones. The direction of the arrows helps show the task sequences.

To create a standard PERT chart, follow these steps:

1. Make a list of the tasks involved in your project.

2. Determine dependencies between tasks.

3. Draw the relevant arrows and nodes to create the chart.

4. Document the time allocated for each task.

When the chart is completed, you can start analyzing the timeline and determining how long the project will take. If you aren't satisfied with the chart’s timeline, this is the perfect opportunity to make adjustments.

There are many advantages to using PERT charts. Let’s take a look at the main ones.

Simplicity

The main advantage of a PERT chart is simplicity. Its minimalistic visual representation of the project allows you to digest information quickly to make informed decisions sooner than by using other tools.

Excellent visualization

Complex projects can be hard to grasp, organize, and manage. Even experienced project managers who know all the details about a project can have difficulty seeing the big picture well enough to make schedule adjustments as the project evolves.

A simple PERT chart can solve this by quickly putting the entire project in perspective. After one look, you can identify potential problems and opportunities to implement solutions.

Critical path identification

The critical path is the longest sequence of dependent tasks in a project. Knowing the critical path is key when managing projects. By using a PERT chart, you can see how to optimize tasks or reduce scope to complete them on time. It can also provide a more accurate estimation of how fast the team can finish tasks and the project as a whole.

Identifying a critical path takes seconds with a PERT chart.

Individual task analytics

Besides showing the big picture, a PERT chart can also help you evaluate individual tasks and see how they contribute to the project timeline. You can reorder tasks to identify and improve the critical path, leading to an optimized project.

You can also determine which resources are needed for tasks to maintain the deadline.

Coordination

Creating a PERT chart allows you to streamline cross-departmental collaboration more easily. When each team can clearly see its role and tasks, they can immediately understand that everyone is dependent on each other and the order of tasks. They can also see how they contribute to the critical path and when tasks become sensitive.

A PERT chart isn't just a tool for project managers to plan and schedule a project. It's a comprehensive solution that allows the entire team to see task statuses, dependencies, and critical paths. These charts help you to make time-related predictions that can affect the timeline, allowing you to engineer adjustments before the project goes off track.

Despite numerous advantages, there are also disadvantages to PERT charts.

Not easy to create

The main disadvantage of a PERT chart is that while it looks simple, it's not easy to create. Creating realistic elements requires skill and experience that not all project managers have. As you’d expect, the more complex the chart is, the longer it takes to create.

Time focus

Time is the key control element of a PERT chart, so it may not be highly useful for projects without strict deadlines.

Poor flexibility

PERT charts don’t work for several projects that are simultaneously dependent on each other. If two projects depend on each other, a PERT chart may not be able to track them effectively.

Short-term

The chart may not be useful for long-term projects. The more complex and diverse a project, the harder it is to create a viable chart. This is because correctly altering the duration and placement of tasks can be difficult.

Similar to a PERT chart, a Gantt chart is a popular project management tool. It is also a visual representation of a project, including activities, dependencies, and timelines in a linear format.

A Gantt chart consists of a list of tasks represented by horizontal bars of different lengths, depending on how long they take. The chart shows the task sequence duration and start and end dates.

The goal of a Gantt chart is to demonstrate which tasks are dependent on each other and identify opportunities for project optimization.

Sounds like a PERT chart, doesn’t it? Maybe, but there are some key differences between PERT charts and Gantt charts:

• PERT charts are harder to interpret for large-scale projects

• A PERT chart is a network diagram, while a Gantt chart is a sequenced bar graph

• PERT charts use strict formulas for time estimation, while Gantt charts allow for changes when deadlines are missed

• Gantt charts are more flexible as you can make simple adjustments mid-project, unlike PERT charts

• PERT charts are better at showing task dependencies than Gantt charts

• Gantt charts usually appear more complex than PERT charts

Both PERT charts and Gantt charts are useful project management tools that can be used together. You can use a PERT chart when planning a project and a Gantt chart while the project is running to make adjustments while the team is active in the execution and delivery of tasks.

Project managers tend to use PERT charts when they need a timeline evaluation and have to find the critical path to maintain a strict deadline without missing vital tasks.

You can take advantage of a PERT chart if you need to:

• Determine the critical path for a project

• Identify task dependencies

• Clarify the scope of work

After using a PERT chart to plan a project, you could benefit from leveraging a Gantt chart. For smaller-scale projects, PERT charts can be useful throughout the project as well.

PERT charts can be highly useful as a project-planning tool for you to optimize task duration and meet deadlines. However, creating and analyzing effective PERT charts requires extensive expertise and experience.

If you have PERT chart experience, they can become integral to any project and help you achieve desired results while keeping the project on schedule.

If necessary, you can insert a dummy activity to create a logical path between two activities. However, it can't be done with the same arrows in common so you want to make sure you have two different beginning and endpoints.

There are three steps to calculating the PERT chart critical path:

1. Record the start and end times of each activity.

2. Review the end time of the last activity in a sequence to determine the duration of the full sequence.

3. Then you will be able to see the sequence with the longest duration to know which one is the project's critical path.

CPM (Critical Path Method) is a project management tool that helps manage specific activities within the project. By contrast, PERT focuses on comprehensive time management to achieve faster project completion.