I know how it works an its completely arse about face! All manufacturers issue manuals which carefully prescribe a sensible set of SOP's for end users to adopt but for reasons known only to themselves they feel that they know better and will tweak and fiddle to make their own set of rules unique to their airline. Which is totally bizarre. What they should do is feed back the way things work and get the manufacturer to collate the input from all their end users and the manufacturer should refine the procedures which the end users then stick to. That way every end user will trend towards best practice and the manufacturer will refine their products towards what the end user wants.
Which SOP that is different from the manufacturers SOP is the one in your operation that makes your operation just that little bit safer? If it exists, why are you not sharing it with everyone else that operates your type? Through the manufacturer like it should be! (I'm using "you" generically, not specifically but I am interested in which particular SOPs are so important that they need to be different to what the manufacturer reccomends)
I can't give you the name of any Boeing or Airbus test pilots because I don't know any but I met an ex Bombardier test pilot who had done a lot of the development and test flying on the Global express (the type I fly) and he had 10 years of airline experience following his air force flying and interspersed his test flying with Bombardier with line flying a corporate jet.
In the corporate world, SOPs tend to develop in a company because of cock ups and patches get put in place to avoid them happening again. Usually this is because there was a departure from the manufacturers SOPs in the first place. Or a new chief pilot wants to make his or her mark on a company so says "do it like I do it because its the best way".
Whats the justification for SOPs being different in different companies? Surely that means they're not standard doesn't it?