Companies tend to minimize the impact of basic cleanliness on equipment / components. Maintenance usually emphasize in condition monitoring programs such as vibration, temperature (motors, bearings....), on-the-run inspections and others.
Equipment condition monitoring results can depend upon cleanliness of equipment. High vibration can come from a loose hold-down bolt, which sometimes cannot be inspected due to debris build-up on top of it. Motor core temperatures reading may not be accurate due to the build-up around casing and cooling fins. There is a high possibility of oil contamination checking dip sticks or adding oil when dust & debris build-up is around. A dirty coupling guard can obstruct the inspector of noticing a recent broken seal.
Equipment / component cleanliness efforts should be present in down-day or shutdown schedules. On-the run inspections should always include check for equipment cleanliness.
Responsibility of who should clean it is like the Chicken-egg dilemma, who came first? Should operators be responsible or it is a maintenance task?
How I see it, there should be a one-time effort to get the equipment in a stable and clean state. This should be led by a maintenance crew and scheduled during down-days or when the equipment can be down. After that, operators should include in their responsibilities keeping / maintaining that equipment clean. Maintenance crews can be part of keeping the equipment clean when performing a maintenance work order on that equipment. We can summarize this approach as:
If something is spilled over it - you clean it (Operators)