The Analogous Estimating Method uses attributes and values from previous projects that are similar to the current project. In its essence it is a technique for estimating duration or cost of an activity based on historical data available from previous projects.
Analogous estimating uses parameters from previous projects such as task durations, performance factors, unit placement ratios, values, attributes and measures of scale become the basis of estimating the activity durations of the new project. This technique relies on the actual duration of previous, similar projects as the basis for estimating. Adjustment for complexity e.g. quality requirements, design requirements, performance factors among others may be required.
When should I use analogous estimating?
Analogous estimating is less costly and less time-consuming
Analogous estimating is less costly and less time-consuming but it is also less accurate. In the industry it is common to use this method to certain parts or segments of the project in conjunction with other estimating methods. The risk is that the estimating team might assume that an activity is the same by its initial appearance but in fact differ significantly due its specific design or material requirements.
Analogous estimating is often used in initial phases of feasibility studies where little details about the project are known.
