Easi , It happens a lot more than you would think. What I cannot figure out is how the big lift companies make any money to off set this practice, When I worked for the beige painted forklift company I would drive about 2 hrs customer do a 1 hour pm only to be sent back the next month to do the same thing on another lift or pallett jack. No matter how much I could not get them to put all 10 units on one PM list so they could be done in one trip. Full maintence units on top of that. Go figure.