There are several sacastic joke-like saying in the Navy about every monthe totally disassembling a machine that is working perfectly, inspect every piece, re-assemble, test and return to service. That is probably the best procedure for infantry with firearms but does not translate well to machinery in redundant systems. The annual inspection requirements for general aviation aircraft in the US is a good idea but produces big errors that sometimes are gross enough to be found by pilots during preflight. Things like inspection covers either missing or just not restored to position, dry battery cells, dead batteries, water in pitot-static tubing, low pressure in tires, etc.
Generally speaking, if something works, best leave it alone and just work it for a reasonable length of time. Fix it when it malfunctions. Have all the sights, smells and sounds of normal operation committed to sensory memory. Investigate changes in same.