So I think you are looking for something that everyone thinks should be easy enough, but most erp doesn’t do. Basically, if you have parts that you for the most part want to make on the job with everything else, but sometimes(key word) you happen to have some extras laying around that you want to use up instead of making new ones. You want the system to automatically see that and call to use them instead of make new ones. It can’t/won’t do that out of the box. The way to manually do it , is the change the field on the job called “pull quantity” to what you want to pull from inventory. But you have to make something to look for those cases. When building a job, the system will not do it automatically. After you change the pull qty, it will change the lower lever requirements, and you use the issue assembly screen to issue them to the job.
Note: if I’m wrong and there is a way to do that automatically, someone please speak up. This would really help us out.