What is the primary focus when using the three estimates for activity duration?

The primary focus when using the three estimates for activity duration—optimistic, most likely, and pessimistic—is the most likely estimate. This estimate represents the duration that is considered the most realistic or probable based on the information available and past experiences. It accounts for the best understanding of the activity's potential duration, balancing both the optimistic and pessimistic scenarios to provide a credible prediction.

The most likely estimate is crucial in project management and planning because it serves as a foundation for more comprehensive analyses, such as calculating expected duration and risk management strategies. It helps project managers make informed decisions and allocate resources effectively, providing a better basis for planning than just relying on the extremes of the optimistic or pessimistic estimates.

Ultimately, focusing on the most likely estimate ensures that project timelines are more accurate and reflective of actual working conditions, fostering better communication and stakeholder expectations.