Personal warranty in Inspection Control
A key aspect of Inspection Control procedures is having qualified personnel involved in signing the status of a part or a test. Personal warranty can be defined as:
“An inspector or operator who signifies the status of an inspection or test by stamping the part and/or associated paperwork and is qualified to determine that status and personally saw or performed the work as stated in the build record” .
Figure 1: Image courtesy of NASA STEP .
It is critical that engineers and others have good plans to ensure that the build paper is correct and has a logical flow for inspection and testing. The inspector evaluation is based on this build paper. Fulfilling these responsibilities guarantees that the existence of a stamp is an indication that correct actions were performed to meet requirements.
As part of the inspection procedures, management should provide authority to qualified personnel to stop production and reject work if it is not acceptable.
Qualities for an Inspection Control System
For an inspection control system, Integrity and Competence are the most important qualities. Remember: “A stamp is a pledge given by a responsible individual who guarantees that he or she performed or witnessed a particular step in the build process” . In another way: “A stamp, electronic or physical, must be a professional, individual guarantee that the operator or inspector personally saw or performed the work, inspection, or test literally as stated in the build record” . As an example in the aerospace industry, NASA has requirements to fulfill related to Personal Warranty, particularly for a Government Mandatory Inspection Point or “GMIP”. As 8735.2 Chapter 8 Section 3 points out:
“Personnel responsible for the administration and performance of Government Mandatory Inspection Points (GMIP) shall: Periodically sign a statement indicating that they understand that their signature, application of a stamp, or data entry is a professional, individual warranty (guarantee) that they personally examined the product, witnessed the process, or verified the record as literally stated for the acceptance criteria.”
Today most organizations have procedures and training programs and procedures for those operators or inspectors who are issued stamps. The organization must safeguard that only the qualified personnel with the correct authorizations and certifications are allowed to apply stamps or make stamp data entries, and also that they maintain control of their assigned stamps.
Let's review: Personal Warranty means:
Finally, the website "Career Igniter"  has an interesting video  that describes the career of a control inspector, it shows the responsibilities and training required for the job in industry in general:
As of general interest, we want to share a couple of videos that shows inspection control procedures in different industries. The first one from "QC InTouch", a company that provides manufacturing, inspection and testing services in China , the video  presents tablet screen inspection and testing. The second video is from the "Automotive Zone" Youtube channel , the video  shows Toyota production line quality control and inspection procedures: