Critical Path
The critical path is the longest sequence of activities in a project schedule network diagram that determines the shortest possible project duration.
Explanation
The critical path represents the sequence of dependent activities that takes the longest total time to complete. Every project has at least one critical path, and some projects have multiple critical paths of equal length. The length of the critical path defines the minimum possible duration of the project; the project cannot be completed any faster without compressing activities on this path.
Activities on the critical path have zero total float, meaning they have no scheduling flexibility. If any critical path activity is delayed by even one day, the entire project will be delayed by one day (assuming no other changes). This makes critical path activities the highest priority for schedule monitoring and control.
A project can have multiple critical paths, which increases schedule risk because a delay on any of the critical paths will delay the project. The critical path can also change during the project as activities are completed ahead of or behind schedule, or as changes are made to the project scope, resources, or constraints. The near-critical path (the path with the smallest amount of float that is not zero) should also be monitored closely, as it can become the critical path if delays occur.
Key Points
- •Longest path through the network diagram
- •Determines the minimum project duration
- •Activities on the critical path have zero total float
- •A project can have multiple critical paths, increasing risk
Exam Tip
The critical path is the LONGEST path, not the shortest. Multiple critical paths increase project risk. Always monitor near-critical paths as well.
Frequently Asked Questions
Related Topics
Critical Path Method (CPM)
The Critical Path Method (CPM) is a schedule network analysis technique used to estimate the minimum project duration and determine the amount of scheduling flexibility (float) on the logical network paths within the schedule model.
Float (Total Float and Free Float)
Total float is the amount of time an activity can be delayed from its early start without delaying the project finish date. Free float is the amount of time an activity can be delayed without delaying the early start of any successor activity.
Schedule Compression
Schedule compression is a technique used to shorten or accelerate the project schedule duration without reducing the project scope.
Develop Schedule
Develop Schedule is the process of analyzing activity sequences, durations, resource requirements, and schedule constraints to create the project schedule model for project execution, monitoring, and controlling.
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