Clause 4.1.1.1 states that each contractor or manufacturer shall conduct tests required by the code to qualify their WPS. It would seem that the manufacturer would use personnel that are employees, but it isn't defined.
The Engineer can permit the use of standard WPSs, which are founded on PQRs submitted by various manufacturers is a case where the testing is performed by every Tom, Dick, and Harry that was kind enough to provide them to AWS free of charge. The company that elects to use the standard WPS doesn't get to see the PQRs or the ranges of the welding parameters used to qualify the WPS.
I would be strongly tempted to use the concept of the standard WPS as justification that anyone can qualify the WPS as long as the manufacturer or contractor is willing to sign the dotted line accepting responsibility for the WPS used for production. Why should AWS be the only entity (that allows anyone to qualify the WPS) that sells the product?
Just to be clear, I don't care for the concept of the standard WPS because there is much valuable information to be learned when a company follows the process of qualifying the WPS. Those lessons are not learned by buying the WPS from AWS or anyone else. It's like going to college to earn a degree and buying your term papers and laboratory reports off the internet. Colleges and universities understand students do not learn from having someone else do their homework. I don't believe my good friends Lawrence or "fbrieden" would give their students passing grades for buying their homework from a student of a previous class or off the internet. In the same manner, companies don't learn the lessons that need to be learned when they buy their WPSs from a third party whether the third party is AWS or "Billy Joe's House of WPSs".
Companies need to develop their own in-house welding guru. The process of qualifying WPSs in-house provides the opportunity for the "guru-wannabe" to learn how to control the welding process and what does and does not work. The employer can speed the process by hiring one of the few welding engineers available or they can spend time to develop in-house expertise by attending the "School of Hardknocks".
Best regards - Al