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Posts Tagged ‘critical path’

Whitbread World Sailboat Race: Optimum Cost/Time Scheduling With Project Priority Matrix

May 24th, 2013 2 comments

This post builds on the principles discussed in the article Calculating Optimum Cost/Time Project Schedule to calculate the optimum cost/time schedule for the Whitbread World Sailboat Race project. It demonstrates how to construct a priority matrix for the Whitbread World Sailboat Race project to determine whether each of the criteria (time, performance, cost) can be constrained, enhanced, or accepted. Based on this matrix, it then calculates the optimum cost/time scheduling to determine whether the project can be completed within 45 weeks and within the planned budget of 3,200,000$.

Improving Scheduling Using Critical Chain Project Management (CCPM)

April 12th, 2013 4 comments

On December 17, 2002, Shelby County Habitat of Humanity, a nonprofit ecumenical housing ministry, broke the world record for the fastest habitat house ever built in 3 hours, 26 minutes, and 34 seconds. Chad Calhoun, the project manager, attributed the project success to the careful planning of each activity, the readiness and organization of all the resources and materials, and the serious commitment to the sensitive schedule. The project kicked off at 11:00 AM on December 17th with the prefabricated wall panels already set in place and ready to be lifted. This was immediately followed by raising the interior panels which lasted exactly 16 minutes as planned. A series of tasks were later executed by dedicated workers and involved plumbing, wiring, carpeting, flooring, painting, and installation of lightnings, cabinets, electrical outlets, windows, and porches. The construction of the 14,000-pound roof was taking place simultaneously on the ground. Upon completion, it was lifted using a crane and attached accordingly. During that time, another crew of workers was busy handling interior work like decorations while others were planting shrubs in the yard. The house was completed around 2:21 PM.

Categories: Time Management

An Example Scenario Using Program Evaluation And Review Technique (PERT)

April 2nd, 2013 2 comments

This post demonstrates how to use PERT (Program Evaluation and Review Technique) to compute the weighted average duration, standard deviation, and the variance of each activity in a given project. It then calculates the average or expected project duration, which is the sum of the average activity times on the critical path. Finally knowing the average project duration and the variances of all activities, the probability (Z) of completing the project by a certain time is then calculated using standard statistical tables.

Categories: Time Management

Sample Forward Pass / Backward Pass Calculation With Lag

December 30th, 2012 6 comments

In the article Sample Forward And Backward Pass Calculation, I explained how to calculate the critical path duration of a given set of project activities assuming only a Finish-To-Start relationship. This post provides a detailed explanation for calculating critical path duration, Early Start date(ES), Late Start date (LS), Early Finish date (EF), Late Finish date (LF), Free Slack (FS), and Total Slack (TS) of a given set of project activities connected together through different types of relationships (Start-To-Start, Finish-To-Start, or Finish-To-Finish) with lag.

Categories: Time Management

Calculating Optimum Cost/Time Project Schedule

September 20th, 2012 3 comments

This post demonstrates how to calculate the optimum cost/time schedule for the given project network below.

Categories: Time Management

Sample Forward And Backward Pass Calculation

August 14th, 2012 3 comments

This post provides a detailed explanation for calculating critical path duration, Early Start date(ES), Late Start date (LS), Early Finish date (EF), Late Finish date (LF), Free Slack (FS), and Total Slack (TS) of a given set of project activities. Assume a Finish-To-Start relationship between each pair of activities. If you want to learn how to calculate the critical path of a set of project activities connected through different types of relationships with lag, kindly check out my article Sample Forward Pass / Backward Pass Calculation With Lag.

Categories: Time Management