When dispatched to repair a failed system, the main job of a service technician is to get the system up and running again. However, a good technician will also make sure the equipment is not wasting energy.
A refrigeration system can be a major draw on electrical energy, so it can be a real benefit when a technician also can make sure the system is operating efficiently. Some of this goes hand-in-hand with repair, as many system issues will cause the equipment to consume excessive energy.