From my previous experience, “Operating Philosophy” is very specific on how they design the platform (for offshore) and plant (for onshore). It tells about how the process sequence take place for example for fire water system, when it triggers to start fire water pump, what pressure jockey pump to start and to off, which pressure transmitter will gives the signal, which is standby which is main pump, what indication will be indicated at DCS and all of this already specified during basic engineering design document.
It very specific on the unit itself for example utilities unit, processing unit, firewater etc.