Critical Path Method (CPM) — definition
Scheduling technique that identifies the longest sequence of dependent activities determining the minimum possible duration of a project.
The critical path method calculates the earliest and latest start and finish dates for each activity, identifying which tasks have no schedule flexibility, or float, and therefore directly determine project completion. Delays to critical path activities delay the overall project, while delays to non-critical activities may not.
Why it matters to industrial buyers
Identifying the critical path allows project teams to focus monitoring and expediting resources on the activities that actually control the completion date.
Key reference points
Key concept
Activities on the critical path have zero float, meaning any delay to them directly delays project completion.
Common tool use
Critical path schedules are commonly maintained in project scheduling software and updated as progress is reported.
Commonly confused with
Work breakdown structure
A WBS defines what work exists; the critical path method sequences that work in time to determine overall project duration.
How it is used in practice
The project schedule shows that equipment delivery, not civil works, sits on the critical path, so the team prioritises expediting the equipment supplier.
Frequently asked questions
Can the critical path change during a project?
Yes, delays or accelerations elsewhere in the schedule can shift which sequence of activities becomes critical.
What does float mean in scheduling?
Float is the amount of time an activity can be delayed without affecting the overall project completion date.
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Related terms
Work Breakdown Structure (WBS)
Hierarchical decomposition of a project's total scope into progressively smaller, manageable work packages used for planning, costing and scheduling.
Milestone Schedule
Summary schedule identifying key project dates and deliverables, such as design approval, factory acceptance, delivery and commissioning, used for high-level tracking.
Risk Register
Documented log of identified project risks, including likelihood, impact, ownership and mitigation actions, maintained and reviewed throughout project execution.
Lead Time
Elapsed time between order confirmation and delivery or readiness of equipment for shipment, encompassing engineering, manufacturing, testing and logistics.
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Reference content only. Global B2B Group is independent of equipment manufacturers and financing institutions; definitions are provided for education and do not constitute engineering, financial or legal advice.