How to Make a CPM Schedule: CPM Scheduling Basics


Project managers know the critical path. It’s the longest sequence of tasks that must be completed to deliver the project, and these tasks are referred to as critical activities. Delaying any of them delays the overall schedule. A CPM schedule or critical path method schedule uses the critical path when scheduling a project.

Using a CPM schedule gives project managers valuable insights into the planning phase of their projects. It also helps keep the project on schedule by focusing on what must be done and knowing what can be skipped if necessary. Every project manager should have a CPM schedule in their toolbox. Learn how to make one, leverage some free templates to help and find out how CPM software facilitates the process.

What Is a CPM Schedule?

A CPM schedule is used to plan and control a project. It identifies the activities that will take the longest amount of time to complete that project while still delivering all critical activities. This is called the critical path and it controls the project duration. A CPM schedule gives each activity an early start date and a late start date. This timetable is visualized in a network diagram or Gantt chart.

A critical task has a zero run-time reserve, which means if the task duration changes, the schedule of the entire project will be affected. This is a negative impact that’ll end up being not only costly but will also add time to the schedule and possibly introduce risks. That’s why critical tasks in a CPM schedule require control and timely detection of risks.

The critical path method is widely used in the transportation market, but it can apply to construction, aerospace and defense, software development, research, product development, engineering and plant maintenance projects, just to name a few. CPM schedules are so widespread because they visualize the schedule graphically and prioritize the critical activities that need attention.

Determining the critical path is time-consuming and project managers have turned to project management software to help. But not all software has that feature. ProjectManager is online project management software with robust Gantt charts that filter for the critical path. There’s no work for you other than a keystroke. Our Gantt charts also let you set a baseline once you’ve made your project plan. Now you can track your planned effort against your actual effort in real time to help stay on schedule. Get started with ProjectManager today for free.

ProjectManager's Gantt chart
ProjectManager has Gantt charts that filter for the critical path in your schedule. Learn more

For What Is a CPM Schedule Used?

A CPM schedule is a planning technique that helps project managers see what must be done in their projects and how long it’ll take. It provides insight when planning a project, allocating resources and, of course, scheduling tasks or activities.

Project managers use a CPM schedule for both current and future projects because a CPM schedule can evaluate expectations and compare them to actual progress. The data collected in the project you’re working on now can help you schedule the next project more accurately.

Scheduling isn’t only about duration and deadlines. There are resources that must be allocated. A CPM schedule makes resource management more effective by allowing project managers to prioritize tasks because they can see when and how they’ll need to best deploy them.

Even the best schedules are going to run into issues that will cause delays. Project managers work to avoid issues that can negatively impact the project’s timeline. A CPM schedule does this by helping them avoid bottlenecks. Bottlenecks can be avoided by knowing the tasks that can and cannot be run in parallel when scheduling the project.

What Should You Include in a CPM Schedule?

To make a CPM schedule, you first have to know its components which are listed below.

  • Tasks: One single unit of work in a larger chain of activities that leads to a deliverable or completed project.
  • Earliest start date: The earliest point in the schedule on which an activity can begin.
  • Latest start date: The latest point in the schedule on which an activity can begin.
  • Earliest finish date: The earliest point in the schedule on which an activity can end.
  • Latest finish date: The latest point in the schedule on which an activity can end.
  • Crash duration: The shortest amount of time to complete an activity.
  • Task dependencies: When one task must end or begin before another can begin or end. There are four types of task dependencies—finish to start, finish to finish, start to start and start to finish.
  • Project milestones: A major point in a project schedule, such as the start or finish of a project phase.

How to Make a CPM Schedule

Now that we understand the terms, it’s time to create a CPM schedule. This can be done over the course of the below seven steps. As you can see, it takes some time. While important to understand, project management software like ProjectManager does this work for you. Simply filter for the critical path and you’ll see it on the timeline of your Gantt chart. But if you don’t have project management software, then follow these steps.

1. List All Your Project Tasks

To begin, you must know all the activities that’ll make up your project. A work breakdown structure (WBS) is a tree diagram that allows you to identify all deliverables in the project and the tasks that’ll create them. Your final deliverable is on top and all those activities that lead you there are hierarchically listed below. Once you’ve completed a WBS, you’ll have all the work necessary for the project schedule.

2. Estimate Start and Finish Dates

The next step is to estimate the duration of each task you identified in the previous step. Not only will you try to figure out how long each task will take, but you want to determine as best you can the start and finish dates. Meet with your project team to help you get the most accurate forecast. They’re skilled and experienced so their input is invaluable.

3. Determine the Slack for Each Task

Slack, also called float, is the amount of time that a task can be delayed without negatively impacting the next task and the overall project schedule. In other words, when a task has slack, you know it can be delayed for a specific amount of time. This is called a non-critical task. No activities on the critical path have any slack and cannot be delayed. That’s why they are critical to the project.

4. Identify Task Dependencies

As the name suggests, a task dependency is one that relates to another. Tasks that are dependent must be identified as they can cause bottlenecks later in the execution of the project. As defined above, there are four types of task dependencies and you should note which type of dependent task each one is. When you identify the task dependencies in your project, you’ll be able to better determine the project’s critical path.

5. Draw a CPM Diagram

In order to perform critical path analysis, you need to draw a CPM diagram. This is a type of network diagram and will take time and a lot of manual work (unless, of course, you use project management software). Be careful, doing this by hand is more likely to produce errors that can mess up your results.

6. Identify the Critical Path

Now that you’ve drawn a CPM diagram, you can identify the critical path. As stated above, it will be made up of activities that have no slack. The critical path is the activities on your CPM diagram that cannot be delayed. It is the longest duration in the project.

7. Finish Your CPM Schedule

With the critical path identified, you can now schedule your project. It’s easy to see the critical tasks and the non-critical tasks. You have also identified task dependencies, which will help you avoid bottlenecks. But once you’ve scheduled the project, you’re not done. You’ll need to review and revive the schedule as you execute the project. Any issues or delays will impact the critical path and you’ll likely have to redo it over the course of the project’s life cycle. Continue to analyze and update the CPM schedule throughout the project.

Free Project Management Templates

As you can see, a lot of work goes into making a CPM schedule. There are, however, some shortcuts that can help. ProjectManager has dozens of free project management templates for Excel and Word that cover every phase of the project. Here are a few that can make a CPM schedule less arduous.

Project Timeline Template

A CPM schedule is a way to create a timeline for your project. Whatever method you use, having a visual timeline makes it easy to manage, track and share that schedule. Our free project timeline template for Excel is made up of two parts. One captures your tasks, start and end dates and duration in a spreadsheet. The other side is populated by that data on a timeline.

Work Breakdown Structure Template

You can make a CPM schedule without using a work breakdown structure, but if you want to ensure you don’t overlook any activities, it’s not recommended. With our free work breakdown structure template for Excel, you can lay out your project from the final deliverable down and not neglect anything crucial that’ll delay your project execution.

Project Task Tracking Template

Of course, having a CPM schedule is only the start. You have to implement it. In order to stay on schedule, you’ll need to track the execution of your tasks to ensure they align with your project plan. That’s where our free project task tracker Excel template comes in. It captures all tasks and dependencies as well as the start date and planned and actual end date to help you stay on track.

ProjectManager Helps You Stick to Your CPM Schedule

Templates are helpful when creating a CPM schedule, but once you execute it, you need project management software to keep to that schedule. ProjectManager is online project management software that delivers real-time data that help you make more informed decisions as you manage your project’s schedule.

Track Your Progress With Real-Time Dashboards

When you set a baseline to your schedule on our Gantt chart you now are able to monitor your project in real time. The data you review is current to help you catch issues before they become problems. Our live dashboard automatically pulls that data and displays it in easy-to-read graphs and charts showing time, cost, workload and much more. There’s no time-consuming configuration needed as with lightweight competing software. Our dashboard is ready when you are.

ProjectManager's dashboard
Automate Simple Tasks and Focus on Critical Ones

A CPM schedule is divided between critical and non-critical tasks. The latter can still take time. Using our workflow automation frees up your team to concentrate on critical tasks for the project. Set up custom workflows, workflow automation and task approvals to create strict rules for the path of a task. You can define which users can approve the task as it moves through its various stages to ensure that only quality gets through. Make as many triggers as you need to change the status of the task, tags, assignees and much more.

ProjectManager's workflow automation

There are many other features in our software that help you deliver your project on time and within its budget. Whether it’s task management, resource management or risk management, you have control in real time to pivot as necessary to keep everything on track. Plus, customizable reports give you more detail and can be easily shared to keep your stakeholders updated. Don’t make or manage your schedule without our software.

Related CPM Schedule Content

You can take a free trial of ProjectManager and test out the software yourself. But if you’re still looking for more information about the critical path and schedules, then we have some links for you to follow. ProjectManager isn’t just software. We’re an online hub for all things project management. Besides software and templates, we publish weekly blogs, guides and tutorial videos. Here is a sampling.

ProjectManager is award-winning software that empowers teams to plan, manage and track projects in real time. Our collaborative software connects everyone, whether in the next office or across the country, enabling them to share files, comment and more. Join teams at Avis, Nestle and Siemens who use our software to deliver success. Get started with ProjectManager today for free.

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