D..
I'm not in IE anymore. Haven't been for a while. But when I was, as an IE rep I worked with the ctr mgrs and made the plans. But occasionally, either my mgr or the region IE had me change the plans and lower the volumestops planned. They always want the plans tight, What got me was one of my elements I got graded on was my accuracy for plan vol and stops. Often (not always), my initial plans were better then the final plans they made me change to. The ironic part then is because they made me change the goals I got a lower performance score.
That is exactly why there should not be any region deptartments. You had a good plan, your boss got a call from the Region IE, who had to approve the plan, and adjusted the plan, not to the advantage of the district, division or operation. Then you take a hit on your evaluation.
I hope your manager made a notation on your evaluation as to what caused you to miss that element. As that was not reflective of your hard work to make a plan that is fair for all involved.