The KC-46 program is supposed to produce new jet tankers to replace the Eisenhower era KC-135 tankers that are still in service with the Air Force. It's a reasonable program to have, tankers get a LOT of use, and everything has a service life. The KC-135's have been flying, hard, for 60 years, and there comes a time when a new aircraft is indicated.
The idea was to buy Boeing 767 airliners, remove the seats, and install fuel tanks and a refueling boom. Take advantage of the well proven, reliable Boeing design, hundreds of which are still flying passengers today.
The Air Force couldn't resist the urge to gold plate. USAF has been into gold plating since I was in the service and that was a long time ago. USAF insisted on rewiring the entire plane. The new wiring scheme called for double and triple redundancy on a lot of circuits, and shielding and separation to prevent electrical crosstalk in the wire bundles. Boeing has built 6 aircraft and now, finally, the Air Force inspectors noticed that some of the new wiring wasn't up to spec. The commercial 767 had about 70 MILES of wire in it. The Air Force added another 50 MILES of wire.
The commercial 767 flies just fine, has been flying just fine for 20 years with the standard wiring system. There was no need to change anything. The Air Force insisted upon messing up a good thing, and it has bought them a 3 month program slippage. Good work USAF. My tax money at work.