Guide
The critical path method (CPM) in project management
The longest chain of dependent tasks that sets the shortest possible project duration.
A project’s critical path is the sequence of tasks that determines the calculated start or end date of the project. Developed by Walker and Kelley in the late 1950s, the Critical Path Method (CPM) helps managers identify the minimum time to complete activities and set realistic schedules.
How CPM works
CPM needs three elements: a full task list, the dependencies among tasks, and an estimated duration for each. By identifying the longest chain of dependent activities, teams see which tasks have slack and which cannot be delayed without extending the timeline.
Why it matters
Critical path analysis reveals dependencies and constraints, estimates task and project duration precisely, prioritizes work by slack, flags tasks that must finish on time, and supports schedule-compression techniques.
Key elements
Earliest/Latest Start (ES/LS), Earliest/Latest Finish (EF/LF), and Float (slack). Critical-path tasks have zero float — any delay delays the whole project.
CPM in FoxPlan
FoxPlan compares planned vs. actual schedules in real time. Its Gantt chart simplifies critical-path creation, highlighting critical tasks and identifying delays that could affect the project outcome.
