Critical Path Method (CPM)
Scheduling Terms
Reviewed by forProject Technology - updated Sep 2026
Quick definition: Critical Path Method (CPM) is the scheduling calculation that turns task durations and their logical relationships into dates — determining when each task can start and finish, how much float each one has, and which sequence of tasks sets the project's finish date.
CPM works in three steps. The Forward Pass moves through the schedule from the start date to calculate the earliest each task can start and finish. The Backward Pass works back from the finish date to calculate the latest each task can start and finish without delaying the project. The difference between the two is Total Float. The tasks with the least float form the Critical Path — the sequence that determines the project's end date.
Why it matters
CPM gives schedulers an objective, calculation-based way to find where schedule risk is concentrated, rather than relying on guesswork. It's the foundational technique behind virtually all modern project scheduling software.
Also known as
N/A
Used in
Critical Path Analysis; Critical Path identification; Integrated Master Schedule development
See also
FAQ
What does CPM actually calculate?
Three things: the earliest each task can start and finish, the latest each can start and finish, and the Total Float between them. The tasks with the least float form the Critical Path.
Can CPM be used without scheduling software?
In principle yes, by manually calculating early and late start and finish dates, but in practice virtually all real projects use scheduling software to run CPM calculations.
Definition maintained by forProject Technology.
© 2026 forProject Technology, Inc.
© 2026 forProject Technology, Inc.
