In project management, particularly when tracking project benefits, it is essential to have well-defined KPIs to measure performance effectively. If KPIs are not yet defined, the project manager should collaborate with the benefit owner, who has a vested interest in the project's success. Together, they can identify the missing data, define the KPIs, and determine the best approach to track and report the KPIs. This collaborative effort ensures that the KPIs are aligned with the project's objectives and the benefit owner's expectations1.
References:
"30 Important Project Management KPIs (& How To Track Them)" from ClearPoint Strategy2.
"14 Project Management Metrics & KPIs You Need to Track" from FounderJar3.
Discussion on ExamTopics regarding project management and KPIs1.