What is a PERT Chart?
PERT stands for Program (or Project) Evaluation and Review Technique, an approach for analyzing and presenting the tasks involved in a project. The PERT chart is a diagram displaying the data produced with that method, mapping out and tracking the tasks and timelines of a project. You can think of the chart as a visual representation of the project schedule.
It comprises nodes and arrows depicting activities or events and connections between them. The (numbered) nodes symbolize milestones, events, or series of tasks. As for the arrows, which can be directional or divergent, they show the sequence or flow of events.
PERT charts were reportedly first used by the U.S. Navy in the 1950s. It has since then been used in a variety of industries and endeavors, including for the 1968 Winter Olympics.
How is the PERT Chart Beneficial?
The following are a few of the benefits that this tool offers:
Breakdown of complex projects into simpler tasks – Project managers commonly use this chart for making projects that are large or complicated simpler. Also, by looking at it, you can have a good idea of the complexity of a project and how to progress from one task to another to complete it. The chart can help you to better estimate the amount of time a project will require and the resources necessary to complete it.
Visualization of responsibilities – With a PERT chart, it becomes more obvious to know who is responsible for what. It helps in organizing and tracking the work of all relevant departments. This chart can promote great communication between departments, thereby aiding the achievement of the overall business goals.
Smooth progress – By showing dependencies, a PERT chart can be useful for detecting possible snags in a project. This enables you to develop plans beforehand on how to deal with these issues as they come.
PERT Charts vs. Gantt Charts
The PERT chart bears some similarity to another popular project management tool, the Gantt chart. They are both schematics of the project schedule. However, there are differences between them.
Project managers often use a PERT chart for breaking down and scheduling more complex projects, usually before starting. Gantt charts can also be used for complex projects, but they commonly follow more into projects. You will find a Gantt chart more suitable for smaller projects.
Perhaps, a clearer difference is the form these tools take. A PERT chart is a network diagram or free-form flowchart. As for a Gantt chart, it is a bar graph featuring horizontal bars that represent tasks and project phases and whose lengths are determined by estimated timeframes.
PERT charts are more useful for showing or setting task dependencies, compared to Gantt charts. With the latter, each bar does not easily show how a failed task can impact another or the project. Arrows on PERT charts reflect inherent dependencies between tasks.
How to Create a PERT Chart
Here are the key steps to follow to draw an effective PERT chart:
Identify milestones – Begin by establishing the activities or milestones of a project. Determine the main phases and break your milestones down into relevant tasks.
Decide sequence – Next, you want to work out the steps to follow for executing tasks. Use arrows to show how one task links to another.
Draw diagram – Using the identified activities, tasks, and sequence of tasks, build your chart. Represent each milestone by a numbered node and list the tasks to complete between nodes. Use arrows to show the sequence of tasks and activities.
Estimate the time required – Come up with a timeframe of how long it will take the team to finish each task along the arrows. Treat the estimated time as the deadline for a task.
