Which estimating technique involves aggregating estimates from detailed components to create an overall estimate?

The technique that involves aggregating estimates from detailed components to develop an overall estimate is known as bottom-up estimation. This method focuses on estimating the costs or durations of each individual component or task in a project and then summing these estimates to establish a comprehensive view of the project's total scope and requirements. It promotes a detailed understanding of each part of the project, allowing for accuracy in the overall estimation.

Using bottom-up estimation is advantageous because it provides a higher level of detail and encourages input from team members who are familiar with the specifics of the tasks. This thorough approach helps identify nuances that may not be captured in methods that take a broader view, thus resulting in a more reliable overall estimate.

In contrast, top-down estimation relies on high-level information to make broader assumptions about costs or timelines, which can overlook specifics. Expert judgment involves seeking insights based on the experience of individuals, but it may not always capture all details. Parametric estimation uses statistical relationships between historical data and other variables, which can limit the depth of individual task considerations.