A Mechanic describes his concerns about his carrier's parts compatibility system allowing two different manufacturer part numbers for a B767-200 fuel management panel (FMP); to have the same company part number.

Narrative

The fuel management panel installed in a B767-200 needed replacing. That part number crosses in our parts compatibility system to a different number. When this part was ordered; a manufacturer part number (MPN) of the part received; was not effective for that B767-200 aircraft. If it weren't for the Mechanic researching the part interchangeability; the wrong part would have been installed in the aircraft. The problem is that these two manufacturer part numbers should not have the same company part number. This can cause wrong parts to be installed in the wrong aircraft and makes ordering the proper part; by chance only.Our parts compatibility system is a disaster waiting to happen. This is just one of many problems with the system that never seems to get fixed; and it puts all the responsibility on the mechanics. The Mechanic kept ordering the part until the proper effective part was finally received. No part was available; so they ended up having to rob a part out of an aircraft with the known same effectivity.