The ideal situation is that the $900 bolt would be sitting at the manufacturers stock (only overnight package delivery away) while the $900 is earning interest for the company. Just in time works in an aircraft heavy check environment. Line maintenance, not so much.
Yes, I understand the ‘theory’.
Reduction of inventory also reduces inventory taxes of around 25% of unit costs (in Commiefornia).
Now these costs are transferred to the vendor whom will increase the cost of the piece part, I have seen typically 10% increases by vendors for this service.
Now Joe Mechanic places an expedite order for this now $990 piece part. Joe Mechanic cannot call the vendor directly to place the order. It must be done by the ‘system’. If the piece part is over a certain value (IIRC it was $500 at UA), it may require a supervisors signature and managers approval. 24 hours killed right there, add in if it’s a weekend or holiday and it gets nuttier. Order gets placed and vendor (whom is typically open from 9-5 M-F) sends it Fedex P1.
When the piece part is received, it has to be verified with the 8130 and put into the system by stores for delivery. Depending on the priority that was on the order, delivery may be scheduled along with the regular stores delivery schedule.
Piece part shows up and Joe Mechanic is out sick or on vacation.
In the meantime, aircraft is out of service.
Seen it!
B) xUT