Just as beauty is in the eye of the beholder, so, too, is cleanliness.
Well, from a purely scientific sense, no; a surface is either free from unwanted matter — be it dirt, germs, bacteria, spores or whatever what have you — or it isn’t. But, from an aesthetic point of view, the definition of cleanliness can differ greatly from person to person.
One’s clean can be another’s unkempt. What is mechanically functional to someone can be classified as in disrepair to some else. It is all perspective-based.
Given the inherent cleanliness discrepancy, it is important to view cleaning outcomes from the perspectives of building occupants and not solely on what you and your workers think “clean” is.
The focus of your efforts may be on the obvious things like hard surface floors, carpets, restroom fixtures and windows, but your customers and building occupants may note small details such as air vents, stair railings, trash receptacles and lighting fixtures.
True cleanliness — either that which can be scientifically proven or the basics of how something looks — is all in the details.
You should undoubtedly continue conquering the major things in your facilities but, at the same time, pay mind to the minutia that can either accentuate your cleaning efforts or be an eyesore to discerning occupants.
Similar to the first scratch you discovered on your brand new car, a single soiled surface can become an obsessive focus that deducts from an otherwise clean built environment.