SOPs
For me, the big problem with SOPs is when Chief Pilots who think they know more than the manufacturer start fiddling with them. I have seen so many changes to SOPs over the years by management, changes that were quite stupid and had nothing to do with the original ones supplied by the manufacturer. In one case I had to e-mail the builder for clarification after enduring mass problems with a change done by a large operator and passed by the Government Aviation folks. The reply was " That is why we told you to do it this way". Some don't realize that if you change the SOPs and have an accident, the manufacturer may turn their backs on you.
Unless you design, build, flight test, certify and write the manuals for a particular 'plane, don't mess with the SOPs.
T