job timings

in other walks of life such are service on cars or planes there is frequently an alloted method and time for for completing a job. (assuming an appropriately trained technician with the right tools and materials) is this the same for bike technicians? Do shop managers have a set number of tasks they need to work through? This might be easy to gauge if the job is to "build" bikes as they arrive from a manufacturer

eg unbox, check for damage, final assembly, check brakes headset and gears work, pump up tyres. 20 mins (maybe less given the mess i've seen from some places)

Less easy with a stream of different jobs trickling in which might be more than a simple job.

The reason i ask is i'm surprised at how much of my lunch hour ive just spent on what i thought was a "ten minute job"

I had to change wheels which includes the following

1 put bike in stand
2 remove wheels
3 take cassette from wheel one and fit to wheel 2 (im experimenting with chain and cassette life so not mixing)
4 remove brake blocks for alloy rims
5 replace with carbon specific pads
6 put wheel back in
7 dial out the pads and adjust to reflect much wider rims in wheel 2
8 Check gears working properly still
9 (heres where my timings went awry) notice that the wheel is a little out of true, theres very little clearance so the wheel should be as true as possible
10 remove wheel
11 sit in jig get spoke keys and adjust
12 re fit to bike check gear and brake alignment
13 pump up tyres
14 take bike down and tidy up

HALF AN HOUR i don't really mind since i enjoy the maintenance stuff and i wasn't messing about but i can see how bike shops charge such high fees. Or am i just a slow coach.