Operation Numbers

What is an operation number?
Manufacturers pay a certain amount of time per job. For example: to replace a clutch they might pay 8 hours. The way they control this is by giving it an operation number.
121212 Remove and replace clutch
You can look up in the workshop manual operation 121212 and it will give you step by step the procedure to replace the clutch. In the mechanics write up if you write 121212 Remove and replace clutch there is no need to write step by step what you have done

Old
Remove tailshaft, airlines, electrical wiring, gear selector cables, clutch cable. Remove p.t.o and air tank. Place jack under g-box to support. Remove g-box mounts. Undo bell housing bolts and remove g-box. Remove clutch. Inspect. confirm clutch worn. Reassemble with new clutch,

New
1515 Replace clutch

The operation number will tell you
-parts required to do the job
-associated operations often required when doing the job
.2hr 1212 Connect laptop
.2hr 1313 Read faultcodes
.2hr 1414 Clutch wear test
.3hr 1717 Road test
1hr 1616 Remove and fit p.t.o

Warranty won’t pay for parts that aren’t on the required to do the job list unless you explain why you had to use them
I have found it’s better to do the write up (at least a draft) before you do the job. This way you know what parts are allowed to be replaced. Have a quick skim over workshop procedure. You also now have a target to beat -8hrs for this clutch.

It’s all there because this is how the warranty claims are processed. Some manufacturers have functions to search operation numbers by keyword , or category (engine, transmission etc) or by main part number.
Has the manufacturer put it in a system so mechanics can utilise it? Has your workshop showed you how to use it?