Here is the failure most buyers miss. When a separate packager assembles the kit and a separate logistics vendor moves it, custody is re-established at the seam between them. That seam is where documentation breaks. Each party documents its own leg, but no one owns the full record, so a gap opens exactly where an auditor looks first. The same seam appears in medical device kitting, where assembly and distribution often sit with different companies, and neither one holds the whole story. Picture a kit that leaves the packager in perfect shape. A courier picks it up, holds it overnight, and hands it to a second carrier. If no one logged those hours, the record has a hole. The product may be fine, but you cannot prove it, and in a regulated trial, proof is the product.