Analogous Estimating
Analogous estimating uses historical data from similar past activities or projects as the basis for estimating the duration or cost of a current activity or project.
Explanation
Analogous estimating, also called top-down estimating, leverages the actual durations or costs from previous similar projects or activities to estimate the current one. It relies on expert judgment to adjust historical values based on known differences between the past and current situations, such as complexity, size, team experience, and environmental conditions.
This technique is most useful early in the project when limited detail is available about the current work. It is relatively quick and inexpensive to perform compared to more detailed techniques like bottom-up estimating. However, it is also less accurate because it depends on the degree of similarity between the current project and historical projects, as well as the quality of the expert judgment applied.
Analogous estimating works best when the past activities are substantially similar in nature (not just appearance), the estimators have the needed expertise, and the historical data is reliable. It can be applied at the project level (estimating total project duration based on similar projects) or at the activity level (estimating individual activity durations based on similar past activities).
Key Points
- •Also called top-down estimating
- •Uses historical data from similar past activities or projects
- •Quick and inexpensive but less accurate than detailed methods
- •Most useful early in the project when detail is limited
Exam Tip
Analogous estimating is a form of expert judgment using historical data. It is less costly but less accurate than bottom-up estimating.
Frequently Asked Questions
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