Does your company hear the phrase "I don't know who did a better job"?

It's one of the most common complaints I hear in my HR consulting practice. It's performance review season, and employees are saying, "I worked so hard, but..." and managers are wondering, "How the hell am I supposed to evaluate anyone?" It's a frustrating cycle on both sides.

I remember one IT company in particular where there were two employees doing similar work on the same team, one working around the clock to fix bugs, the other leaving work on time and focusing on improving the user experience. Who should get a higher score on their year-end evaluation?

The old system didn't give us an answer - simply "hours worked" or "workload handled" didn't measure true performance.