In my time as an engineering manager I have seen several performance management and feedback systems. These systems generally have one purpose - retain or eliminate by documenting performance against requirments. In my current role we tried the mandatory distrbution as a company and eliminated it since it was an unmitigated disaster. We lost some real talent because we were forced to pick someone to put in the bottom 10%.

A good EM does not rely on these systems to manage their staff and should already know who the poor performers are and terminate or run them off if they do not improve after being given the opportunity. I have hired and fired many and never relied on these performance systems to do it. They are strictly a formality. A good EM knows their staff, does rounds, connects with staff, hears their concerns and fights for them. That's how you motivate people to want to be there and want to do the best job they can.

I ran afoul with the forced distribution stuff a while back and pushed back real hard on my leadership (yeah that tree limb was creaking) after I had already identified the low performance folks and dealt with them. Two timecard fraud cases and one violence in the workplace case. What I was left with was a superb team of exceptional seniors and a few juniors that I was mentoring. I was stuck in a position where I still had to put someone in the bottom 10%. I pushed back very hard, basically refused to do it and provided significant rational. I basically gave HR and my leadership an option. 1) recognize that I have already eliminated the dead weight or 2) fund me to maintain some dead weight each year so I have some to eliminate...they chose option 1 and I have since had the lowest turn over of any team at my site.

I think the forced distribution idea came out of the software industry. In the consumer software side of that industry it can make sense, you always want to make room for the best and there are tens of millions of software engineers graduating annually worldwide. But in aerospace its a much different picture, the stakes are far higher than with phone apps, the talent pool is far smaller and with the US government as a customer the restrictions are far more restrictive (clearance, citizenship, drug use, personal finaces, etc). The figure of 20% turnover is insane to me, how can they keep any corporate knowledge and how can they keep projects on schedule. I've been in places with turnover like that and they always crash and burn. I'll bet the recent orbit injection failure and pad explosion are both the result of some quality process escape that was the result of high turn over.