A story about how individually-driven KPIs rarely consider team-driven work, despite the fact that the latter is often the key ingredient in building efficient and effective departments.
Specifically, a look at Tim, who consistently scored zero on their internal developer KPI, because they spent their entire time pairing with other developers, and how this work directly improved team morale and code quality across the board in ways that would have not been possible without Tim around:
You see, the reason that Tim’s productivity score was zero, was that he never signed up for any stories. Instead he would spend his day pairing with different teammates.
Tim wasn’t delivering software; Tim was delivering a team that was delivering software. The entire team became more effective, more productive, more aligned, more idiomatic, more fun, because Tim was in the team.
On how moving from individual KPIs to team-focused ones often provide better business value:
... we quietly dropped the individual productivity metrics in favour of team accountability, where we tracked—and celebrated—the business impact we were delivering to the organisation as a high-performing unit.
Just don’t try to measure the individual contribution of a unit in a complex adaptive system, because the premise of the question is flawed.