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Static Critical Path-What’s that?

By Rufran Frago posted 09-12-2021 08:47 PM

  

A photo-grab of the primary critical path of the schedule being analyzed before the start of the SQRA is shown below.

This is the project’s primary critical path generated from Primavera that can be used in contrast to the quantified criticality resulting from running a schedule quantitative risk analysis. The latter provides a semblance of dynamic criticality brought about by multiple simulation and iteration. I call the criticality result of schedule quantitative risk analysis (SQRA) as dynamic critical path (criticality index).

The critical paths from SQRA are in reality, more dynamic in nature than static. Multiple iteration demonstrates the changes a schedule undertakes after each task is updated. It means activities, specially those with high criticality can switch paths, with some ending up as non-critical.

What one can glean from a P6 deterministic schedule at a given time are static critical paths. It is essentially just a snapshot of the paths in time. That snapshot is equivalent to a singular iteration run using our risk analysis tool such as OPRA or Acumen Risk. Never rely on static path with blind confidence. It is best to regularly crosscheck with periodic schedule risk analysis.

About the Author:

Rufran C. Frago is the Founder of PM Solution Pro, a Calgary consultingproduct, and training services firm focusing on project and business management solutions. He is passionate providing advice, mentorship, education and training through consultation, collaboration, and what he uniquely calls, student-led training.

BOOKS AUTHORED BY RUFRAN FRAGO

  1. Risk-based Management in the World of Threats and Opportunities: A Project Controls Perspective.ISBN 978-0-9947608-0-7.Canada
  2. Plan to Schedule, Schedule to Plan.ISBN 978-0-9947608-2-1.Canada
  3. How to Create a Good Quality P50 Risk-based Baseline Schedule.ISBN 978-0-9947608-1-4.Canada
  4. Schedule Quantitative Risk Analysis (Traditional Method).ISBN 978-0-9947608-3-8.Canada
  5. RISK, What are you? The Risk Management Poem: Children’s Book for all Professionals.ISBN 978-0-9947608-4-5 (Canada)


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09-17-2021 08:08 PM

Hi Pushpendra,

SQRA takes the three points estimate representation of each activity and divides it into equal segments. The tool samples a random segment in each iteration. Randomness makes it less likely but possible that the same sample segment is selected more than once.

Each iteration is a “what-if” scenario of the project. One thousand iterations are like looking at 1000 project scenarios and examining its primary critical path. This means that a thousand iterations are like looking at the same project one thousand times, with a different situation each time. Five thousand iterations are like looking at the same project using five thousand times what-ifs. The value of each three points range contributes to the resulting overall probability distribution. Setting and examining the near critical path of say 10 or 15 days float in P6 doesn’t matter much, in my opinion, when doing the quantitative risk analysis. That setting is more on appreciating a singular static path rather than the dynamic path represented by the Criticality Index.

Considering activities with Total Float equal and less than 10 days or 15 days can be important when identifying activities that will be ranged. This is an exercise worth doing prior to running SQRA. 


RCF

09-16-2021 12:37 PM

Thanks, Rufran for sharing your thought on how can critical path can impact  SQRA . Wondering your thoughts on considering the critical path equal and less than 10 days or 15 days of the total float can provide more accuracy in SQRA results.