Lesson 10: Project Management PERT/CPM

There are two reasons why this may not be a simple task.

1) Some tasks may need to be complete before other tasks can commence, and 2) uncertainty on how much time is required to complete each task.

If you do a network analysis, why would you be interested in the latest start time of any activity?

Because we want to know how long the activity can be delayed without affecting the project completion time. Latest activity start times affect the project completion time.

CPM

Critical Path Method

It seems to me that for a simple project with just a few tasks involved, the use of a Gantt chart would work just fine. In this case, I don't see the need to do a PERT/CPM analysis, do you?

I agree that a Gantt chart will do the trick for a simple project.

How do you know if an activity is on the critical path?

If the slack of that activity is zero. Zero slack time means that this activity cannot be delayed without delaying the entire project

PERT

Program evaluation and review technique, for planning and coordinating large projects.

Why is determination of the critical path important?

To determine those tasks, which if delayed, will delay the project to the same degree. The critical path, by definition, consists of those tasks, which if delayed, will also delay the project, and to the same degree.

What is the best method of planning a project?

Use the PERT/CPM techniques The PERT/CPM technique enables you to answer questions concerning the project that could not otherwise be answered.

Which of the following is NOT a question to be answered by network analysis?

What is the total cost of an activity? This is not a question that can be answered by network analysis.

I like the idea of being able to use PERT/CPM to analyze a major project, but it seems to me that it would be a very difficult procedure in the case of a large, complex project. Do you agree?

Yes and no. If you do the analysis by hand, it would be very time consuming, but not really difficult. The calculations are all simple arithmetic. However, I would recommend use of a software package. There are several good ones available on the market.

PERT and CPM are used to plan,

schedule and control a wide variety of projects

If tasks are not accomplished in the proper order,

the cost of the project will be higher, and the completion time will be much longer than is necessary.