W12_Anton_Schedule Risk Assessment

1.      Problem Recognition, Definition, and Evaluation

Base on productivity and volume of work for earth work job, duration of each activity for schedule development was calculated as on table1.


Relation of activities was Finish to Start.

Risk for those activities are identified and quantified as on table 2.


Need to develop schedule with consider the risk have occur on assesment.


2.      Development of the Feasible Alternative

To develop schedule with consider the risk, Triangular distribution and PERT method is tools apply for risk assessment.

3.      Development of the Outcomes and Cash flows for Each Alternative


LOW RANGE  =   Duration

MOST LIKELY =   Duration x Low likelihood x Impact

HIGH RANGE =   Duration x High likelihood x Impact


4.      Selection of Criterion (or Criteria)

Duration for development schedule should include quantified risk and impact identify

5.      Analysis and Comparison of the Alternative

Expected duration from triangular distribution is the average of Low range, most likely and high range.

PERTH was provided lower result on expected duration and provided standard deviation and variance.

6.      Selection of the Preferred Alternative

PERTH method was prefer alternative, it’s provide more detail analysis for option (of duration) regarding level of confidence / accuracy.

7.      Performance Monitoring and Post Evaluation of Result

Risk management uses the result risk assessment to work for the best out comes, but even the correct decision may be accompanied by unfavorable result that have a low probability of occurance1.

Even with a well-disciplined risk analysis, management may make bad decision with good information and bad result can happen even from good decision1.

8.      References :

1. Humphrey and Associates (2012), Project Management Using Earned Value, Chapter 17. Pp. 325 – 334, Second Editions, Humphreys & Associates, Inc.

2. John K. Hollman (2012), Total Cost Management Framework, Section 7.6 pp. 163-176, 1st edition revised, AACE International.

3. Scott, Dr. Amos, PE (2012). Skills and knowlage of Cost Engineering, chapter 31 pp 31.1 – 31.8,  5th edition,  AACE International, Createspace.

This entry was posted in Anton. Bookmark the permalink.

1 Response to W12_Anton_Schedule Risk Assessment

  1. drpdg says:

    Hmmmmm……. Pak Anton, you really need to go back and do more research on this before you repost a revision……

    First, Triangular Distribution and PERT are NOT two different methods at all…… You can apply PERT to either a BETA (i.e. Poisson) or to a Triangular Distribution, the objective being to turn either the Beta (Poisson) or Triangular distribution INTO a normal or bell shaped distribution. You missed that whole point.

    A second big mistake you made is on your PERT calculation sheet, you ADDED up the total Standard Deviations (54.1) this is absolutely, totally a no-no!!! What you do is add up the sum of the VARIANCES (839.8) and then find the square root of that number, which is 28.97 or call it 29 days, and not the 54.1 you are showing…

    And the third and REALLY big mistake is your durations are WAY too long……. Go download the GAO “Best Practices in Scheduling” http://www.gao.gov/products/GAO-12-120G and check to see what it says about project durations….. Assuming you are reporting on a monthly basis, then no activity should be longer than the reporting period…… So how do you get activities which are 84 and 168 days long? How can you possibly track, much less report accurately on this project.

    Bottom line- Sorry, but I have to reject this posting and send you back to do more research on how to use PERT PROPERLY. Redo this and repost it as W12.1

    Also, I strongly urge you do review the GAO Scheduling Best Practices and use that as the basis for ANOTHER blog posting, comparing what your schedule looks like against the “best practices”….. (Like where is your start and finish milestones…..???)

    Another great topic for a blog posting would be to Google on “Line of Balance” method and “Roadwork”. Then show us how the “LoB method” can help you do a better job of managing this project.

    Dr. PDG, Jakarta

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s