These things are a little more complex than they first appear..If you realize that performance has to be aggregated and reported up the food chain, then you'll understand why even a very competent manager cannot really afford to measure performance by the metrics he believes to be most accurate, just the ones that are easiest for his Boss to understand and send up the food chain.
Unfortunately, your job as a "mid-level manager" is not to get your unit functioning with the utmost efficiency. Rather your job is to make you own Boss look as good as possible, while making sure your unit/group continues to function at an acceptable level.
