You mean to say that the metrics are applied post-hoc. I.e. you reward last month's efficiency this month.
Otherwise, you incentivize poor performance all the time, so that I can show massive improvement on this month's "efficiency push", next months "productivity (lines of code, completed stories) push", the "bug bash", etc.
Otherwise, you incentivize poor performance all the time, so that I can show massive improvement on this month's "efficiency push", next months "productivity (lines of code, completed stories) push", the "bug bash", etc.