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Critical Path Length Index

Critical Path Length Index (CPLI)

Scheduling Terms Reviewed by forProject Technology - updated Oct 2026
Quick definition: The Critical Path Length Index (CPLI) measures how realistic the project's completion date is, based on the remaining length of the critical path and the total float available to the completion task.

CPLI = (Critical Path Length + Total Float) ÷ Critical Path Length. Critical Path Length is the number of working days from the status date to the early finish of the task or milestone that marks completion; Total Float is that task's float, which can be positive or negative. A CPLI of 1.0 means the critical path is exactly on plan; above 1.0 means there's room to spare; below 1.0 means the work must go faster than planned to finish on time. For example, 200 days remaining with 20 days of float gives a CPLI of 1.10. The DCMA 14-Point Assessment flags a CPLI below 0.95.

What this means for you

CPLI turns critical path float into a single efficiency number: how hard the remaining work has to be pushed to meet the completion date, and whether that's getting easier or harder over time.

Also known as
N/A
Used in
DCMA 14-Point Assessment; critical path analysis

FAQ

What does a CPLI below 1.0 mean?
The completion task has negative float, so the remaining critical path work must be done faster than planned to finish on time.
Can CPLI be measured to an interim milestone?
Yes. It's often calculated to a key interim milestone as well as to project completion.
Definition maintained by forProject Technology.
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