PERT Chart Template

What is a PERT Chart Template?

A PERT chart template is a pre-built tool for planning a project as a network of activities, where each activity carries three time estimates rather than one. PERT stands for Program Evaluation and Review Technique, and the chart shows activities as boxes connected by dependency lines, running from a start point to a finish. It is also called a PERT diagram or a PERT network diagram.

The method survives because of the estimating, not the drawing. Few teams now hand-draw a full PERT network, and most modern project scheduling software builds the network for you.

What remains everywhere is three-point estimation: asking for a best case, a most likely case and a worst case, then weighting them. That gives you a spread as well as an average, which is what makes a probability question answerable at all.

What's Included in a PERT Chart Template: Key Components

A PERT chart needs five things per activity: an ID, what it comes after, and three time estimates. Everything else calculates from those.

Two calculated outputs sit above the activity rows. The critical path is the longest chain through the network, read off the least float rather than off zero, so it still identifies correctly when an imposed date makes every float positive or negative.

The nearly critical band catches activities with float above zero but under your threshold. Those are the ones nobody watches, and they become the critical path the first time anything slips.

The workbook also draws the network itself. Boxes and dependency lines build from what you type, with the critical path in red, so you never draw a diagram by hand.

PERT Chart Example for a Construction Project

Here's an example of a PERT chart template completed for a depot refurbishment, showing all fifteen activities from start to finish.

Read the boxes first. Early start, duration and early finish sit along the top, late start, float and late finish along the bottom. Every red box has zero float and forms the critical path, eleven of the fifteen activities here.

The four green boxes are where the slack is. Facade procurement carries 37.8 days of float, so it can slip more than a month without moving the finish date. That is the value of a network over a bar chart: it tells you which delays matter and which do not.

How to Create a PERT Chart in Excel

List every activity, give each one three estimates and say what it comes after, then let the forward and backward passes calculate the rest. The template below does the arithmetic and draws the network as you type.

1. Set the project, the start date and the calendar on Setup, since every date counts forward from there
2. Choose the estimating convention, either PERT weighted at (O + 4M + P) ÷ 6, or triangular, which averages the three equally and runs more pessimistic when the worst case sits far out
3. Set the near-critical float threshold and the confidence level you want the date question answered at
4. List one activity per row with a best case, most likely case and worst case
5. Enter the predecessor IDs in the After columns, and keep every activity below the rows it comes after, since a spreadsheet cannot resolve links pointing upwards
6. Clear the Check column before reading anything else, because it names each fault in words and colors the row until you fix it
7. Read the critical path off the network, then read the nearly critical list beside it
8. Set a target date and read the probability, keeping the merge point count next to it in mind

Excel does the calculation but not the scheduling. There are no lags, no leads, no resource levelling and one calendar, and each of those can move a real critical path.

Once the program needs any of them, construction project scheduling software is the right home for it and the PERT estimates carry across.

PERT vs CPM vs Gantt: Which Schedule Method to Use

PERT estimates how long activities will take under uncertainty, CPM finds the longest path through a network of known durations, and a Gantt chart displays a schedule against a calendar. They answer different questions and most projects use more than one.

Which is better, PERT or CPM?

Neither. They share the same forward and backward pass, and the only real difference is whether durations come from one estimate or three. That is why the two are usually written together as PERT/CPM, and why a construction program normally runs both: three-point estimates on the packages nobody has priced yet, single durations on the trades you have built fifty times.

The wrong method is whichever one pretends you have certainty you do not have.

Use PERT when durations are genuinely uncertain, such as early planning, first-of-a-kind work, or anything where you are being asked to commit to a date you cannot yet defend.

Use critical path analysis once durations settle and the question becomes which activities to protect. Use a Gantt chart to communicate the result, since a network diagram is a planning tool and a Gantt is a reporting one.

Related Articles and Templates

• Critical Path Analysis
• Free Float vs Total Float
• Schedule Risk Analysis
• Integrated Master Schedule
• Construction Scheduling