When creating your quality management system, whether it be ISO9001:2000 or another quality system, you will have to determine your inspection criteria. You’ll probably have a receiving inspection and a pre-shipping inspection to contend with. You might also have one or several in-process inspections, depending on your operation.
The bottom line is that you want to make your customer happy, and you want to be profitable. Your inspection criteria may literally be dictated by your customer, or it could be your own criteria based on experience with your customers. Your inspection criteria may also be government mandated.
In the aircraft parts world where I come from, there are many criteria that need to be met before receiving parts into stock, and before shipping to customers. There may be government regulations that apply, depending on your operation. Certain aircraft parts require documentation such as an FAA Form 8130-3, or the European equivalent JAA-1 form.
Certain life-limited parts, such as turbine engine disks, also require paperwork tracing how many hours and cycles the part has been thru. While there may be no government mandate dictating you have certain documentation, it is highly unlikely you will find a customer for your product if you do not have the correct paperwork.
Some small parts, such as standard hardware, may need only a certification from the manufacturer, or “manufacturer’s cert”. And, actually, there is likely no government regulation covering paperwork requirements for such small parts. But despite no regulations, again, you’ll probably have a hard time selling any aircraft part without documentation as required by your customer.
Specialized industries often require specialized criteria for inspection. It is in your best interest to know what your customers’ requirements are, and any applicable government regulations, when you are determining your company’s various inspection criteria.