Project Tools: Analogous Estimating

One of the tools you can use for project activity duration estimating is analogous estimating. The dictionary defines analogous as "being similar in some particular way."

Think of the similarities between the human brain and a computer. One of the similarities is that they both process and store information. The similarities between the human brain and a computer make them analogous.

Project managers can use similarities between project activities when they are estimating activity duration. This technique of using similarities is called analogous estimating and involves the use of the actual duration of a previous, similar activity as the basis for estimating the duration of a future activity.

Sometimes referred to as top-down estimating, analogous estimating is used when there is a limited amount of detailed information about the project. This is especially true in the early phases of project planning.

Analogous estimating saves project managers time and money because it enables them to avoid the cost of hiring experts. However, project managers must be careful when using this tool. It is most reliable when:

• both activities are similar in fact and appearance
• the individuals preparing the estimates have the needed expertise.

Analogous estimating can be a powerful tool when used properly. When using this tool, always ensure that the two projects are similar in appearance and fact. Also, make sure that the person who performs the estimates has the necessary experience. Analogous estimating can help you ensure that you accurately estimate the duration of project activities.