How to Use PERT to Find the Critical Path in Projects

Have you had to whizz through tasks before a go-live? Or juggle back-to-back project deadlines?

Whether this is an occasional or a regular occurrence, it’s frustrating. But there’s a solution: the Critical Path Method (CPM) and the Program Evaluation and Review Technique (PERT). Think of the CPM as a GPS for improvement and PERT as a turbocharger for execution.

Both methods are now PMO gold standards across industries. Combine them, and you’ve got next-level project management magic—PERT Critical Path.

This blog explains the key concepts, benefits, and six simple steps to apply them—plus how ClickUp can help you nail both seamlessly.

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⏰ 60-Second Summary

Understanding PERT and CPM: PERT focuses on managing uncertainties with probabilistic time estimates, while CPM maps fixed durations to identify critical tasks
Why should you combine them? Blend PERT’s adaptability with CPM’s structure for better risk management, resource allocation, holistic planning, and improved decision-making
Steps to apply PERT and CPM:
- Define all project activities and involve cross-functional teams
- Sequence tasks and map dependencies
- Create a network diagram linking tasks and milestones
- Estimate task durations using the PERT formula
- Identify the critical path by calculating task slack
- Monitor progress and adjust timelines as needed
Solutions that help overcome challenges
- Task tracking may get overwhelming and is best addressed with dedicated tools like ClickUp‘s project management software
- Demands intensive, accurate time estimations that best come from ClickUp’s automated formulas
- Collaboration with multiple teams gets cumbersome and requires a feature-rich documentation tool like ClickUp Docs

How to Use PERT to Find the Critical Path in Projects

What Is PERT?

Program Evaluation Review Technique (PERT) is a network planning tool to design, schedule, and steer complex projects. Think of it as your project’s crystal ball, helping you account for uncertainty and lead to an optimized timeline.

How? It focuses on precise, probabilistic time estimates of each activity. Implementing it visualizes key tasks, milestones, dependencies, and activity durations.

Components of PERT

Here are the key components of what makes up a PERT chart:

Component	What it means
Node	Marks the start or end of activities Each node is often either an event or milestone related to the project’s progress
Arrows	Visualizes the task flow and dependencies while linking two nodes Each arrow represents the sequence and the activity required to reach the next milestone
PERT time estimates	Describes how long each activity will take and is placed above the arrows Each PERT duration is calculated considering the optimistic and pessimistic estimates

When it comes together, this is how it looks.

PERT chart pert critical path — Source: Geeksforgeeks

The PERT method stands out particularly because of its thorough time estimates. The calculations factor in risks to create a realistic project timeline.

➡️ Read More: 10 PERT Chart Maker Software for Projects

Applications of PERT

With the key components clear, here are a few great applications of PERT:

Product development: It tracks progress in launching new products by focusing on time and milestone charts. PERT keeps teams aligned from ideation to market release. Plus, its granular view is perfect for research and development projects
Project scheduling: PERT organizes tasks in sequence to meet deadlines, ideal for managing complex projects. By breaking the project into smaller tasks, PERT ensures every milestone is achievable
Risk analysis: It identifies potential delays by estimating each task’s best, worst, and most likely scenarios. PERT chart solutions help anticipate hurdles and create backup plans. When applied effectively, it makes a safety net and protection from surprises
Resource allocation: It maps task dependencies to efficiently allocate team members and tools. With PERT, you avoid bottlenecks and team overloads, making it ideal for software development businesses
Event planning: PERT simplifies timelines for events like workshops and corporate conferences. It brings every task on track, from booking a venue to sending invites

That said, creating PERT charts should be simple regardless of the application.

To facilitate this, ClickUp comes with multiple ready-to-use PERT chart templates. Using them only takes a few clicks.

ClickUp PERT Chart Template

Looking for a network diagram solution with no limits? The ClickUp PERT Chart Template fits the bill perfectly. This canvas-style solution comes predesigned with clear nodes, arrows, and time durations.

The template also has a legend section for new users. Every content in that space can be turned into a task with due dates, assignees, and priority levels.

What Is the Critical Path Method (CPM)?

CPM is an approach that maps your project network to improve it. In project execution, bottleneck activities are time and resource hogs. They’re the key areas to address and optimize for smooth sailing.

CPM visualizes the network through fixed task durations, making it easier to identify these constraints. Plus, this method spots the longest sequence of all dependent tasks (a project’s critical path). As a result, you can seamlessly focus your efforts and optimize resource-intensive activities.

Key concepts in CPM

With the basics down, let’s cover the main components of a critical path analysis.

Component	What it means
Nodes	Represents tasks or activities in the project network (unlike PERT) Nodes are often depicted as rectangles and, at times, circles
Arrows	Indicates the sequence of tasks. Arrows connect nodes and show dependencies between activities.
Time estimates	Calculated as fixed durations for each activity Because they are the node’s estimate, they’re placed under the activity name. This makes it simpler to spot the critical path.

There’s no hard and fast rule about the placement of each component. It’s all tweaked to simplify logic and understanding. Since CPM maps tasks with fixed durations, there’s no room for delays. So, project managers also calculate a float or slack in each activity to accommodate surprises.

💡 Pro Tip: Review the meaning of each CPM component. While similar to PERT, each subtle yet crucial nuance changes how CPM depicts your project.

Applications of CPM

Here are a few spaces to put CPM to effective use:

Setup and maintenance review: CPM visualizes routine activities like installation, testing, and final trial runs. It is ideal for improving aspects that must be repeated without deviation. Plus, this method helps avoid overlaps and costly delays during projects like line setups
Fixed process management: This approach simplifies site prep, foundation work, and finishing. It identifies critical activities so delays in one task don’t derail the entire project. This makes it perfect for keeping large construction timelines on track
Layout improvement: CPM optimizes workflows in sequential activities like equipment setup, production, and quality checks. By diving deep into technical processes, CPM is great for minimizing idle time across production lines
Streamlining handling processes: It maps out fixed steps for processes that require physical execution. In logistics, CPM makes it easy to avoid disruptions in storing, retrieving, and transporting materials. This also improves resource flow and drives task and goal alignment

While CPM can also be applied like PERT, it is better suited for stable projects and predictable customer needs. With an extensive library of templates, ClickUp also features ones tailored for CPM.

🚀 ClickUp Critical Pathway Analysis Template

ClickUp’s Critical Pathway Analysis Template is an ideal solution to surface obstacles and key task details. Its standout Gantt chart easily maps task flow and dependencies, while the Calendar View aligns tasks and meetings for seamless team capacity planning.

The template also has a Kanban board that visualizes responsibilities and status to align everyone on the team. Its task lists simplify spotting the critical path using fields like duration estimates.

➡️ Read More: 10 Powerful Critical Path Analysis Software

ClickUp has helped us omit the use of various channels and streamline the conversation for quicker action and resolution as our single platform of truth for project management…Having all of the dependencies, assigned roles, well-documented tasks, and standard documents already thought out in a reusable format will further accelerate our goal of optimizing our workflows.

Tanya Cummings, Director, Digital Experience, STANLEY Security

How PERT and CPM Work Together

There are differences in focus and intent. PERT targets uncertainties, while CPM sticks to fixed schedules. That said, many elements overlap.

Aside from visualization, PERT manages the what-ifs, and CPM ensures when it must happen.

With such innate compatibility, combining the two elevates your project execution quality easily. Let’s dive into this a little deeper.

Combining probabilities with deterministic scheduling

PERT offers probabilistic estimates of task durations, whereas CPM delivers a structure that prioritizes fixed timelines and pre-determined schedules.

One mitigates risk, and the other maintains stability. When combined, uncertain tasks are accounted for with PERT, and CPM keeps the project grounded in realistic, time-bound execution.

Benefits of using both techniques

Here are four key benefits you’re sure to reap with the PERT critical path:

Better risk management: Blending both approaches helps anticipate delays without losing focus on critical tasks. This helps minimize disruptions and handle risks efficiently
Enhanced resource allocation: Both approaches, when combined, improve activity prioritization and milestone visibility. They also enhance your understanding of project dependencies, preventing overloads and challenges
Holistic planning: They visualize fixed steps and uncertain tasks to deliver end-to-end, holistic project planning. Plus, the combination of flexibility with structure leads to accurate timelines and seamless project completion
Improved decision-making: PERT and CPM enable realistic timelines while preparing for surprises. For decision-makers and key stakeholders, this reshapes project stability and progress

➡️ Read More: Want to perfect milestone tracking on another visualization tool? Check out Gantt Chart Milestones: The Ultimate Guide.

Steps to Apply PERT and Critical Path in Projects

With the foundation set, let’s understand how to implement both tools.

🚀 Scenario: We need a product launch for a new smartphone. Here are the six steps involved in applying PERT and CPM together.

Step 1: Define project activities

Start by listing all the tasks needed for the launch.

🚀 How to do it:

Break down high-level objectives into specific tasks (e.g., prepare product demo into develop prototype and test prototype)
Involve all cross-functional teams to identify all essential steps. Better yet, make an engaging workshop out of it

Define project activities pert critical path

💡 Pro Tip: Record all activities in a dedicated document. When multiple teams pitch in, keeping all thoughts in one space also keeps it organized.

Step 2: Sequence activities

Next, arrange tasks in the order they need to be completed. For instance, you can’t test a prototype before developing it, and product design depends on market research findings.

🚀 How to do it:

Use a spreadsheet or planning tool to create a list of task sequences
Map dependencies against each task. This involves arranging what tasks you must complete before moving to the next

Step 3: Create a network diagram

Visualize the tasks and their dependencies in a network diagram.

🚀 How to do it:

Draw nodes for each activity and connect them with arrows showing the sequence
Ensure there’s a logical flow from start to finish

Step 4: Estimate time for each activity

Calculate the PERT time estimate and assign the durations to each task.

🚀 How to do it:

Jot down optimistic, pessimistic, and most likely task durations
Use the PERT weighted average formula:

[Optimistic duration + (4 x Most likely duration) + Pessimistic duration]
_____________________________________________________________
6

Then, map the estimates onto the network diagram

Step 5: Identify the critical path

Determine the longest sequence of dependent tasks in this project.

Disclaimer: The first part (calculating the critical path) is rich in numbers!

🚀 How to do it:

Go from the first step to the last. Record each activity’s earliest possible start and finish times
- Earliest start: Check the previous activity and add its Earliest Finish time with the current activity’s PERT task duration

Earliest finish: Add the current activity’s PERT task duration with the Earliest Start of the same task

Note: The last activity’s Earliest Finish is the total project duration. Here, it amounts to 70.83 days

Go from the previous project step to the first, starting with the total project duration. Here, we calculate the latest possible start and finish durations without delaying the project
- Latest finish: The ‘next’ activity’s latest start time, placed above in your table, will be your current activity’s latest finish

Latest start: Subtract the current activity’s Latest Finish from the PERT task duration to arrive at the newest start duration

The calculation is called a backward pass, and this is what it looks like

Identify tasks with zero slack. Only tasks with zero slack are a part of the critical path, as they don’t have any buffer for delays. Slack is the difference between the earliest and latest start (or earliest and latest finish)

Now highlight all tasks with zero slack on the network diagram to arrive at the Critical Path (highlighted in red)

Step 6: Monitor and adjust

As the launch progresses, track task completion and adapt timelines. For example, the critical path may change if “Beta Testing” takes longer than planned.

🚀 How to do it:

Regularly update the task progress to reflect actual task durations
Compare actual progress with the planned schedule
Review the critical path and analyze if your resources are freeing up or under more burden
Revise timelines, resource allocation, and customer delivery commitments if needed

Common Challenges and How to Overcome Them

While the PERT critical path does drive a project’s progress, it comes with its share of challenges.

Here’s a list of common obstacles businesses face and how to tackle them:

Inefficient task tracking

Tracking activities across a PERT network becomes difficult, especially for larger projects. Critical path activities require constant monitoring to ensure no delays, and multiple tasks and dependencies add to the complexity.

Without a clear tracking system or tool, miscommunication and missed deadlines are unavoidable.

✅ Solution: ClickUp offers a tool to visualize, track, and manage project tasks without complicating the PERT network diagram.

🚀 ClickUp Tasks

From task creation and assignment to seamless execution—ClickUp Tasks is a powerhouse management tool. In addition to mapping project activities, it allows you to create task dependencies within the task. This way, the project flow will be clear and easy to manage.

The tool also helps prioritize critical path activities and keeps everyone in the loop. Plus, you can attach documents, link pages, and subtasks if one task has multiple components.

ClickUp was the best solution for us because it combines multiple project management tools into one. From Mind-Mapping to Documents to Sprints, ClickUp is a dynamic tool to organize any department’s task management needs and give visibility across the whole company.

Andrea Park, Business Operations Coordinator, Spekit

Subjective and resource-intensive estimations

PERT can be inaccurate if not carefully planned or calculated. It depends on precise task durations, which can be unreliable for new or unfamiliar projects. Additionally, its calculations can be hard to follow on the network diagram.

✅ Solution: ClickUp helps map variables with tailored and automated formulas to tackle human error and resource-draining calculations.

🚀 ClickUp Custom Fields

ClickUp Custom Fields is a feature designed to simplify and expand how you map project variables. It allows you to customize data fields to suit your needs, including using conditional logic and advanced formulas. Plus, each field updates in real-time, whether the PERT or individual task durations.

It centralizes all variables and instantly applies the same logic across fields. This eliminates manual copy-pasting and resource-heavy calculations. The result? Consistent, accurate, and reliable estimations every time.

Managing collaborative inputs

Projects often rely on tasks, inputs, and estimates from many teams. To map everything accurately, you need input from all experts, not guesswork. But without a central, collaborative space, things get tricky. Inputs appear scattered, and important details might slip through the cracks.

✅ Solution: The solution is a document where everyone can pen their input. While ClickUp features collaboration in every tool, one documentation tool stands out.

🚀 ClickUp Docs

ClickUp Docs is a dedicated tool with features to strengthen collaboration and simplify documentation. It’s designed to map anything from requirements to protocols. ClickUp Docs also offers live editing and seamless sharing, which is ideal for multiple teams to list project activities.

The tool also features rich formatting to map everything in detail and all in one go. Plus, if each team needs a separate space, ClickUp Docs lets you include multiple subpages.

Fragmented project flow

The PERT critical method optimizes projects through visualization, but planning, tracking, and execution often require separate tools. This can lead to inefficiencies, misalignment, and laborious progress tracking.

✅ Solution: The best solution for this is a unified system. A one-space approach simplifies visualization, progress tracking, and active project management. ClickUp offers an all-in-one platform to refine every stage of your PERT project.

ClickUp Project Management Software pert critical path — Turn ideas into actions, connect real-time dashboards, and integrate task management into network diagrams with ClickUp Project Management Software

The ClickUp Project Management Software is an end-to-end solution that optimizes and executes. It features analytical dashboards to track the results from PERT diagram insights.

That’s not all. The software also helps build visual workflows and network diagrams using visualization tools like ClickUp Whiteboards.

ClickUp Gantt Chat View — *Visualize task dependencies and streamline project plans effortlessly with ClickUp’s Gantt Chart View*

With 1000+ integrations included, connecting external apps and features is simple. The built-in project management tools offer real-time updates, advanced automation, and reporting. It even features Gantt Charts, workload views, and time tracking to maximize efficiency for your project and team.

Plus, access to ClickUp Brain, an AI tool, reduces manual work, delivers clear insights, and facilitates goal review and summaries.

➡️ Read More: Top 12 Project Management Charts

Overcome Certainty and Strengthen Planning With ClickUp

Combining the PERT critical path turns chaos into clarity. Apply it effectively, and you’ll have structured planning, mitigated risks, and healthy project deliverables.

In essence, it lets you eliminate missed deadlines and endless headaches.

While our guide has covered everything, you still need the right tool to blend this power into project management. That’s where ClickUp shines.

In addition to its stunning visuals, ClickUp offers smart AI and automation, seamless task management, and robust analytics in one place. Ready to level up your project mapping? Sign up with ClickUp for free today!