My understanding is that ships designated as military check for failures, while ships designated as commercial do not. So a warship with commercial drives would still have to check for failures, although the drives themselves have a lower failure rate, are cheaper to repair, and are fuel efficient. The problem with commercial drives is they take so much room. The designation of commercial or military is made at the design phase, weapons, sensors larger than 1 hs, flight decks & hangers, military drives, or magazines get a ship a military designation. Apparently military jump drives do not. If a chip is designated as military than all components on the ship are subject to the failure check regardless of whether it is a "miitary" or a "commercial" component.