To make sure that stamps are used correctly, by the appropriate personnel, and that they can be properly read and interpreted, a systematic approach should be used.
We know that Inspection Control is the process of establishing and maintaining a documented stamp and marking material control systems and is normally the responsibility of Quality Assurance. Most aerospace organizations' inspection control systems are based on a requirement for clear and objective evidence that required operations, including testing and inspection have been performed, as also the related records of the current status of the product.
The organization's inspection plans and procedures will likely contain stamp use guidance and direction on :
- Marking materials
- Stamp holder responsibilities
- Electronic data control
- Other general rules
The Inspection Control System Regulates and controls :
- Stamp Ordering and issuance
- Stamp Usage and surveillance
- Stamp design and significance
- Stamp Replacement and cancellation.
Inspection control requirements
Let's take a look at the requirements that NASA has related to the regulation of stamps in inspection control systems, where NPR 8735.2, Section 18.104.22.168 states :
“Where stamps or an electronic medium is used, the inspection control system shall:
- Indicate the date of acceptance.
- Ensure the legibility and durability of stamp impressions and that stamps do not interlock with other stamps.
- Ensure that only properly authorized and qualified persons are permitted to apply stamps or make data entries and that individuals who are authorized to use stamps maintain control of their assigned stamp at all times.
- Ensure that data entries and/or stamp impressions provide direct traceability to the individual applying the stamp or making the data entry.”
The NASA STEP - "Inspection Control and Personal Warranty", SMA-QE-WBT-252 course , gives us some general aspects to keep in mind about the Inspection Control System:
- The operator or inspector evaluates performance of the work as stated in the build paper, so it’s imperative that the build paper be accurate. If the build paper is found to be inaccurate, there has to be a system to make corrections.
- Inspection Control is a team effort. Teamwork means everyone performs his or her job properly for the team to succeed, but it does not mean team members are interchangeable. Each team member has a specific role to play, whether it be design, assembly, testing, inspection, or stamping.
- The responsibility of Management is to make the jobs of operators and inspectors more efficient and to ensure they are properly trained regarding personal warranty, and to give them the appropriate responsibility and authority to implement personal warranty, including the authority to stop work if the work is found to be unsatisfactory.
- Stamp points should coincide with Mandatory Inspection Points (MIPs) and when possible should coincide with natural pause points in the work process.
*Basic figures for Inspection Control System courtesy of NASA STEP .