In a somewhat similar case, grievance 02-12, the arbitrator's ruling in part was based on this:

"As the Association acknowledged, the CBA gives the company discretion in reconstructing the line. The company could have honored xxxxxx's request but it did not have to do so provided that the alternative selected was 1) consistent with the CBA and 2) not the result of an arbitrary and capricious decision"

I feel that in the specifics of my case, the decision to not follow my request was inconsistent with the CBA and both arbitrary and capricious.