Not all work the maintenance department does is maintenance, and not all maintenance work is of equal value. It might seem that if everyone in maintenance is busy the plant is being properly maintained. But this way of looking at things doesn’t take into account priorities or timing. Busy does not mean effective, nor does it mean productive.
For example, maintenance techs might be kept busy doing things unrelated to keeping the most critical equipment running, while resources for less important work are “saved” by skipping some of the maintenance that would keep product moving out the door. This modality is actually typical.
Another way maintenance departments typically “save” resources is by skipping such troublesome, time-consuming maintenance as insulation resistance testing (and trending) on service and feeder cabling.
A better way to use maintenance resources is to prioritize/allocate resources to fully maintaining equipment according to its production value. If you have to incur downtime on a $300/hour line so that a $9,000/hr line stays running, so be it.