W4 _Said Alamri _ Using PERT Method for Estimation a Maintenance Project (Part Two)

1. Problem Recognition

This post will estimate the schedule for a maintenance project for fire water pond leakage which posted in my previous blog W3.1. The critical path is civil works for concreting the pond. In similar project the civil engineer is estimating the time required to do such task based on his experience. Even though expert judgments is an acceptable tool to estimate schedule I will incorporate PERT method with P90 will to estimate the time required to complete the critical path.

2. Development the Feasible Alternative

  • A combination of Expert judgment and PERT method – based on the time it took to do similar tasks on other projects and based on the experience of civil engineer in similar projects
  • PERT – duration based on P95 & P80
  1. Development of the Outcome for Alternatives

PERT Method calculation is illustrated in below formula:



Where X is the Unknown value, M = Mean, STDv = Standard deviation, P95=1.65 from Z table

Solution of formula 1 in Table -1

Table -1 Results of Formula-1

Table -1 Results of Formula-1

4. Selection of Criteria

The critical path for this project is the civil works and there will be some activities before and after starting the critical path. The most accurate method which reflects actual will be selected.

5. Analysis and Comparison of the Alternative

From Table-1 it can be seen that the critical path will 8 weeks with probability of 95% and 7.4 weeks with 80% probability. The results are very near.

6. Selection of the Preferred Alternative

The preferred is P95 and it gives 8 weeks estimation for the civil works.

7. Performance Monitoring and the Post Evaluation of Result

In coming blogs work break down structure for critical path will be established and schedule of the project as will

8. References:

  1. W2_Murtadha_Schedule Estimation Analysis retrieved July 29th  2014 https://pmioman14.wordpress.com/2014/06/12/w2_murtadha_schedule-estimation-analysis/
  2. Six Methods for the Estimation of Activity Duration in Project Management retrieved July 29th  2014  http://smallbusiness.chron.com/six-methods-estimation-activity-duration-project-management-41782.html
  3. Estimating Time Accurately retrieved July 29th  2014  http://www.mindtools.com/pages/article/newPPM_01.htm







One thought on “W4 _Said Alamri _ Using PERT Method for Estimation a Maintenance Project (Part Two)

  1. AWESOME posting, Said!!! Nice work!!!

    My only comment/suggestion is to be absolutely SURE that you reference the GAO’s “Best Practices in Scheduling” especially Appendix 1 and 3. If you use that as a checklist, I can promise you that you will begin to create much better schedules.

    Important to realize in preparation for your PMP or PMI-Scheduling certification is that the GAO Best Practices in Scheduling was SPONSORED by PMI, which means a lot of what is in that book is likely to be found on the PMP and especially the PMI- SP certification exams.

    Another reference you may want to look at is a recent post by one of my other students here in Indonesia. http://kristalaace2014.wordpress.com/2014/06/29/w16-3_andi_produce-water-system-schedule-analysis-with-software-package-part-1/ Andi has become quite expert using @Risk for Project http://www.palisade.com/projectriskmanagement/. IF you want to use that program, you can download it for free and if you need an extension of time, I know the big bosses there and they will be happy to grant you an extension until the end of the class. They especially love to see blog postings where their software is being used…..

    Keep up the really good work and looking forward to seeing more postings like this in coming weeks.

    Ramadhan Khareem!!!!

    Dr. PDG, Jakarta

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