That's actually very common. Large organisations need a way to track how departments consume various shared resources, so they start some sort of internal billi

That's actually very common. Large organisations need a way to track how departments consume various shared resources, so they start some sort of internal billing/cost assignment system. It also allows support departments to measure their efficiency. Sometimes, the "support department" starts selling to external clients as well. Lufthansa Sky Chefs, for example, now delivers food to many airlines. I believe their maintenance operation works similarly. The opposite also happens – where some department chooses an external supplier over the internal one, because the latter is too expensive (low-quality/inflexible/whatever).