Critical Path Method

The Critical Path Method (CPM) is a project management technique used to identify the sequence of crucial tasks that must be completed on time for the entire project to be finished on schedule. This method involves mapping out every task necessary to complete the project, identifying dependencies between tasks, and calculating the longest path of dependencies, known as the critical path. The critical path determines the shortest possible duration for the project.

Key Components:

  • Task Identification: Listing all tasks required to complete the project.
  • Dependencies: Establishing relationships between tasks to understand which ones depend on the completion of others.
  • Critical Path Calculation: Identifying the longest path of dependent tasks, which dictates the project’s minimum completion time.
  • Float Calculation: Determining the amount of time that non-critical tasks can be delayed without affecting the project’s completion date.


  • Timely Completion: Managing tasks on the critical path is essential for minimising delays and ensuring the project stays on schedule.
  • Efficient Resource Allocation: Helps in allocating resources effectively by focusing on critical tasks that impact the overall project timeline.
  • Bottleneck Anticipation: Allows project managers to identify potential bottlenecks and plan for contingencies.
  • Enhanced Planning: Provides a clear and structured approach to project planning, making it easier to track progress and make informed decisions.

Applications in Construction:

  • Project Scheduling: Used extensively in planning and scheduling complex construction projects.
  • Resource Management: Assists in efficiently distributing labor, materials, and equipment to critical tasks.
  • Progress Monitoring: Facilitates ongoing monitoring of project progress against the schedule.


  1. Define Project Tasks: Break down the project into individual tasks.
  2. Establish Dependencies: Identify dependencies and the sequence of tasks.
  3. Create a Network Diagram: Visualize the tasks and dependencies in a diagram.
  4. Estimate Durations: Assign time estimates to each task.
  5. Calculate Critical Path: Determine the longest path through the network diagram.
  6. Monitor and Adjust: Regularly review and adjust the schedule as needed to stay on track.