Assuming you have identified Root Cause and fixed the "quality issues" that keep occurring, as others have pointed out you can ship an Inspection Report with each delivery identifying what each part measured to, feature by feature, when it shipped to them. This does required you to mark each part with some kind of ID/Sequence Number that ties it to measurements on the Report.
Inspection Reporting is simply a certification "quality issues" aren't occurring in the process, so horse has to come before the cart. If quality issues keep occurring, inserting Inspection Reporting into that will won't really fix anything of course. You will still have ballooned overhead/cost trying to correct deliveries.
Alternately, I suppose you could consider a "batch certification", whereby you list all the measurements/requirements for the job and declare that the batch of parts passed those checks successfully. This would avoid having to mark and record measurements for each part.
Where I work, jobs that require Inspection Reporting fall into two categories: Past customer complaint (thankfully rare) versus simply required by a Customer (most common). In either case parts are laser engraved with ID numbers and each is measured and recorded on an Inspection Report. That Inspection report is shipped/e-mailed to the Customer as part of the delivery.
A couple of our Customers have their own revision controlled Inspection Reports we have to use.
I've created a couple of "intelligent" Inspection Report spreadsheets for everyone else. Once measurements are completed it is setup to either 1) Print a formatted Inspecdtion Report, or 2) Produce an "export" of the measurement results that can be e-mailed to the customer.