I do not entirely agree with the view that SOPs should include the abnormal or emergency checklists as suggested by 411A and Rananim in their references to Swiss Air 111. That accident involved poor emergency procedures, which were more in the realms of the manufacturer and regulator. The SOP that was missing was to consider landing asap.
SOPs – Standard Operating Procedures are predominantly for routine operations. Some ‘professionally advanced’ operators have very few SOPs. Their safety culture and operating methods instil their procedures in everyday behaviour - ‘this is the way we do things’.
Therefore, by segregating SOPs from the QRH / abnormal or emergency checklists, the real purpose and value of SOPs, and thence the number required, can be assessed. The number of standard procedures often reflects inversely, the operator’s safety culture.
There are considerable differences between an operator who requires crews to fly by the book and has to write everything down, and a similar operator who teaches airmanship – and as None, 411A, and Rananim indicate, airmanship requires crews to use judgement within a standardised operation.
Now if airmanship (experience?) is really lacking as indicted by Capt. Haddock, then perhaps we should be worried by the increasing number of SOPs.