As it turns out, a significant number of people find the Pro QC site searching for sampling and sampling related terms such as ANSI Z1.4 or MIL-STD-105E (no longer in use). In speaking with organizations, I’ve also detected a certain level of fear regarding how to approach an acceptance sampling strategy.
Fear is unnecessary… In fact, sampling here is nothing more than a tool you’re going to use to provide a realistic (of course statistically relevant) assessment of quality and be able to ultimately determine whether or not product is meeting expectations without having to spend the time and money involved with a 100% inspection. This is a good thing.
Some advice…
Get your specs straight – Before you even start to think about AQLs and defect classifications, go back and make sure you’ve really evaluated your product and have created detailed product specifications. Once you have this information, go through each item and determine how you want to classify nonconformance (major, minor or critical). At Pro QC, we use the following general guideline for defect classifications:
- Critical – Any condition found which poses the possibility of causing injury or harm to, or otherwise endangering the life or safety of, the end user of the product or others in the immediate vicinity of its use.
- Major – Any condition found adversely affecting the product’s marketability and sale-ability or adversely affecting its required form, fit or function and which is likely to result in the end user returning it to the source from which is was purchased for refund or replacement.
- Minor – Any condition found which while possibly less than desirable to the end user of the product, does not adversely affect its marketability, sale-ability, form, fit or function and is unlikely to result in its return to the source from which is was purchased.
- Visual (cosmetic/workmanship) inspection – General Level 1
- Drop-testing (Package integrity ISTA testing) – Special Level 3
- Functional Testing – Special Level 1
- Major Defects 1.5
- Minor Defects, 4.0
- Critical Defects 0.10
