By Ray Myers, Jr., PMP The 8/80 rule is used as a reminder to project managers to limit the size of WBS work packages.  Following these guidelines will prevent micro management or the creation of work packages that become too large to manage. Work packages should be: No smaller than 8 hours No larger...
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By Ray Myers, Jr., PMP A colleague caught me off-guard the other day when he said he could calculate time.  It took me a minute, but I got it.  He was referring to the PERT formula.  Using 3 estimates, you can actually come pretty close to estimating the actual time to perform a task....
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By Ray Myers, Jr., PMP ROM estimates are used for strategic decisions, long range planning, or simply to respond to questions such as: How big is the bread box? or, Approximately, just for grins, how much are we talking about? The first step is to determine if a ROM estimate is appropriate.  Review the...
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By Ray Myers, Jr., PMP There are three types of estimates that may be used for project estimating: Rough-Order-of-Magnitude (ROM) Estimates (-50% to +50%) Budget Estimates (-10% to +25%) Definitive Estimates (-5% to +10%) Some or all of these estimate types may be used on a project. When providing project estimates, be sure to...
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By Ray Myers, Jr., PMP Parametric Estimating is an estimating technique that uses a statistical relationship between data and other variables to calculate the estimate.  It is simply a mathematical model. The complexity of the model may vary based on the nature of the project or activity to be estimated.  For example, you could...
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By Ray Myers, Jr., PMP Analogous estimating is a form of expert judgment   It uses the actual or historical data of a similar project activity for the basis for the estimate..  In other words, those individuals with the most experience are the best source for Analogous estimates. The Subject Matter Experts (SMEs) submit their...
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By Ray Myers, Jr., PMP The Delphi technique uses a number of subject matter experts (SMEs) to develop independent estimates, document assumptions, and discuss the differences. Prerequisites The Project Manager functions as the exercise facilitator A Group of SMEs Project description, scope, assumptions and work breakdown structure (WBS) Steps Repeat this procedure for each...
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By Ray Myers, Jr., PMP A single estimate is not always enough to provide confidence in the accuracy of the project estimate.  By using three estimates, you can incorporate risk factors into your estimates. Using the projects identified risks: Estimate the most optimistic (few risks will occur) Most likely (average number of risks will...
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