Goodhart’s Law states that: “When a measure becomes a target, it ceases to be a good measure.”
The first comment in this Lesswrong’s article about the law is indicative of this phenomenon in industry:
A good example from my history of doing this is when I worked for an ISP and persuaded them to eliminate “cases closed” as a performance measurement for customer service and tech support people because it was causing email-based cases to be closed without any actual investigation. People would email back and create a new case, and then a rep would get credit for closing that one without investigation either. The replacement metric was one I derived via the Theory of Constraints, inspired by Goldratt’s “throughput-dollar-days” measurement. The replacement metric was “customer-satisfaction-waiting-hours” — a measurement of collective work-in-progress inventory at the team level, and a measurement of priority at the ticket level.
KPIs are the biggest culprit. Unsophisticated reasoning and copycat behavior lead many to believe that anything that can be measured should be a KPI and that each KPI should have a goal. If you’re careless, KPIs can become a massive time suck and lead to endless debates about which should be included or discarded. Albeit catastrophic numbers, they rarely nudge anyone to alter their behaviors, making them effectively useless.