Earned value is a method used to measure what aspect of project performance?

Earned value is a project management technique that specifically measures the performance of a project in terms of work completed against what was planned. This method integrates the scope, schedule, and cost of project management, allowing project managers to assess the progress and efficiency of the project as it unfolds.

By comparing the earned value (the value of work actually completed) to the planned value (the value of work scheduled to be completed by this point in time), project managers can gain insight into whether a project is on track. If the earned value is less than the planned value, it indicates that less work has been completed than expected at that point in the project timeline. This metric provides not just a snapshot of the current state of the project but also helps in forecasting future performance and can be used to make informed decisions about necessary adjustments to keep the project on track.

Other options may discuss aspects like actual costs, time spent, or resource allocation, but these do not encapsulate the primary focus of earned value management, which is the relationship between work done and work planned. Thus, the chosen answer effectively captures the essence of what earned value measures in project performance.