Critical Path or Longest Path in Primavera P6, Which Should You Use?
Shimonkepha Onwuneme PMP® PMI-RMP®
EPC Project Planner||Scheduler||Risk Management|| Quantitative Schedule & Cost Risk Analysis ||Project Controls ||Certified Power BI Data Analyst|| Constant Learner||Problem Solving Mindset||Energy Mgt|| EVM||SAP||TILOS
Dear Planners and P6 Users,
Critical path is usually defined in some textbooks as the path with zero total float but then it is not true.
You can adjust your critical path's total float value in Primavera P6 when you want to schedule (F9) your project. Go to options >>Compute total float as. You can even change the critical path to Longest Path here.
In MS Project, go to project options >> Advanced>> Tasks are critical if slack is less than or equal to.
But then, why does P6 have an option of Longest Path for calculating critical path, should you use it and when can you use it?
The reason:
When you have just baselined your project and have not inputted any updates, the option to use the critical path or longest path will not matter. Both are the same at this point!
But when you start updating your schedule, things start to become different!
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The key reason for the longest path option is when negative floats begin to pop up within your schedule caused by:
The main reasons are:
At the point where these reasons will occur on your schedule, it is better to use Longest Path in P6 rather than the critical path!
As Michael Lepage said " the Longest Path is a Critical Path, but not all Critical Paths are the Longest", there can arise a point where on your schedule, you have a path with zero float and another path with negative floats present. Which will you choose as the critical path?
What do you think? Share your thought on the comment section.
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Lead Project Scheduler | Project Control Specialist
1moAll longest paths are in critical paths, not all critical paths are in the Longest paths. Critical paths are as instructed/set in the basis of TF calculation(0 days). In a schedule update, the longest path drives the project completion, not all the critical paths. Hence, corrective/recovery plan focus is on the Longest path during mitigation actions.
Project Scheduling Specialist & Delay Expert @ Vanderlande | CAPM
1moInteresting Topic I have always love to share my insight. I view both from the point of Total Float. The Project duration is calculated based on the difference between the ES - EF. During project execution an activity might be critical and not driving the project Finish date but Longest path define remaining duration based on chain of activities with Late finish dates
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Project Planning Engineer | Power BI & Primavera P6 | EPC Projects Control | 7+ Years in Oil & Gas | I help projects achieve completion on time & within budget
1moInsightful