PMP Exam – Cost Estimating Tools and Techniques

Posted on February 4, 2009 by


So, how much is all this going to cost me? Project Managers must routinely obtain estimates of project and activity costs. The Cost Estimating process (a process in the PMBOK®’s cost knowledge area and planning process group) deals with the task of obtaining reliable estimates for project costs. The Cost Estimating process has three tools and techniques that are specifically meant to obtain cost estimates—Analogous Estimating, Bottom-up Estimating, and Parametric Estimating.

Here are some example of these techniques. The Estemitte family is planning their annual vacation. Mr. Estemitte says that last year’s vacation cost $2,300, so this one should cost about the same. This is an example of Analogous Estimating. Notice that this was a very quick way to obtain a cost estimate and that it may not be highly accurate. If Mrs. Estemitte replies that the cost of travel has increased substantially since last year, and they would obtain a more accurate estimate if they used the vacation expenses of someone who has travelled recently, she is calling into question her husband’s Expert Judgment. Expert Judgment (for example, knowing what vacation or other project to use as a comparison) is critical in order to obtain a cost estimate that has the degree of accuracy needed to be useful.

Mrs. Estemitte breaks down the vacation expenses and obtains costs for lodging, car rental, meals, entertainment, souvenirs, and the pet sitter. She totals all these costs at $3,500. This is called bottom-up estimating. Notice that the more detail she uses to break down the vacation activities, the more accurate her estimate is likely to be. Also, it is likely to be more accurate than Analogous Estimating.

The Estemitte family has decided to go to a local all-inclusive resort, which charges $500 (taxes included)/day per family. Travel and other expenses will be minuscule. They want to have 5 days of vacation, so they calculate that the resort will cost about $2,500. This is an example of Parametric Estimating. The cost per unit is multiplied by the quantity of work. Other examples of units of work could be line of code in programming and miles of highway in construction.