Comment by marcusb

Yes, but service technicians that are paid by the job often find ways to do a job in far less time using a different approach than the manufacturer suggests.

An example: I used to own a Saturn S-series. The manufacturer estimate for replacing the alternator was something like 4 hours of labor, and involved removing the power steering pump (which was above the alternator.)

It was possible to replace the alternator in about 30 minutes by removing the front passenger wheel and mud shield, and then accessing the alternator directly.