From ground level, though, it's really easy to see the dysfunctional cultures growing up around metrics. At the factory where I used to work, we'd zig-zag from metric to metric. Yield one quarter, Cpk the next, scrap rate the quarter after that. Special cross-departmental teams to manage the metric. Regardless of which metric was chosen, people would do really dumb things to try to meet it. If scrap rate was the metric, we'd send terrible material through the line to keep the scrap rate low. If yield was the metric, we'd scrap anything that was even slightly abnormal. Cpk was the worst (or maybe the best), because we just adjusted our spec limits until Cpk was acceptable.

The better managers translated the quantitative metrics into qualitative guidance for their teams. The worse managers provided no such buffer and instead made their teams achieve metrics by any means necessary.