What is Inspection Control?

Inspection control encompasses a series of activities aimed at overseeing a project's inspection process. The purpose of having inspections is to detect and eliminate any defects as early as possible, so as to guarantee the project's success. The Inspection Control System seeks to ensure that the proper inspections do in fact take place.

Important Definitions

An inspection is here understood to be a technical evaluation process during which a product is examined with the purpose of finding and removing defects and / or discrepancies as early as possible in the project life cycle. An inspection can also be referred to as a "product assurance action." For example, an inspection might consist in checking that a certain component is properly connected. If it is not, the problem is detected and addressed before further work is done, further complicating the detection and solution of the problem.

A defect is any occurrence in a product that is determined to be incomplete or incorrect relative to the product's requirements, expectations, and / or standards. In other words, a defect is when a component of a system does not do what it is supposed to do. For instance, a communication system that fails to transmit data correctly is considered defective.

Goal of an Inspection Control System

An Inspection Control System should provide the means for ensuring the following:

1. That appropriate inspection procedures are implemented;
2. That personnel performing those inspections have adequate training and credentials to perform them;
3. That means of certifying the fulfillment of the inspection procedures exist and are properly maintained, together with records indicating the date and person responsible for the inspection.

The most common means of indicating that product inspection took place are:

• Stamps;
• Signatures;
• Labels;
• Electronic media.

NASA’s most commonly used means of indicating an inspection has occurred is a stamp. STEP SMA-QE-WBT-252 defines a stamp as:

“Any means of physically marking a product or it’s associated documentation with an inspector’s unique mark. Sometimes a signature on a separate form can be used for the same purpose”.

In the case of NASA, the accomplishment of product assurance actions can be attested to by a signature, with legible printed name and date or by an inspection control system such as electronic medium or stamps. It is also a requirement to use plain English. It is a good policy to use quality stamps to keep a clear record that work products have been inspected by qualified personnel, and to indicate when the inspection took place. In this course, we will use the term "stamp" to refer to any of these means of attesting that an inspection took place.

STEP SMA-QE-WBT-252 indicates that stamps "are used to indicate the quality status or conditions of material, parts, tools, equipment, assemblies, systems, and / or supporting documentation that have been inspected, certified, calibrated, and/or reviewed."

In any aerospace project, inspection control is a critical area that must be an inherent part of all procedures during project development. This is not only important for the project's internal development, but also because the systems developed will interact with agencies and entities that require these types of certifications and inspection requirements.