Dean,
In a previous life, boards came off of the machines, and went to SMT QC, then to SMT T/U before heading off to wash and through-hole. The concept being that the SMT "team" was responsible for the quality coming off the machine, with QC and T/U thrown in there to counter reality. This allowed (theoretically) early detection of assembly issues which could be fed directly back to the machine operator, and minimized (near eliminated) any bad blood between the thru-hole assembly folks and the SMT assembly folks.
My current shop is quite a bit smaller, and, as such, my SMT t/u folks are the same folks that perform the thru-hole assembly. So, my process is pick/place, SMT insp/t/u, thru-hole, final QC. We've found that this gives us the best speed of processing, with the best opportunity of catching defects prior to final QC.
In both of these instances, I consider these qc/t/u steps to be a part of the assembly process, though we do log the defects as part of the quality process. Sort of a step serving a dual purpose.
I agree with you regarding the "double inspection," however, my experience shows that the real world ends up requiring it. Sending items to formal inspection and logging them all, while valuable for nailing down process issues, could overwhelm your rework operations. If you go to a "formal" inspection, then kick them back for rework, then send them to another inspection to verify the rework has been completed, you are, essentially, performing the double inspection anyway. I've found that doing it up front is faster for the process than doing QC before and after rework. Of course, your mileage may vary.
Over inspection is another story. In a previous life, we discovered that all of our inspectors and rework operators were doing Class 3 work...even when the contract requirements were only Class 2. We discovered that this was a huge waste of money/time. The fix was to re-educate everyone on the actual requirements, and to involve them in the process by teaching them what the overworking was costing us. I would guess that the same goes for your class 3 jobs....introducing them to the concept of overwork, re-educating them on the actual requirements, and spot checking what they're doing. A word of warning, though, this approach will generally lead to a lot of question asking for a little while, while the people get used to the new methods, etc; they'll tend to want to over-do the double checking until their attitudes about being questioned start to diminish.
cheers, ..rob
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