The key to predictive maintenance is that equipment and system condition determines what maintenance is performed, rather than a preset calendar or schedule. In predictive maintenance, there are no preset time frames at disposal when equipments are to be quality checked. This implies that repairs and maintenance are performed at the ideal time, resources are not wasted unnecessarily and equipments are maintained at a higher level of performance. This can extend the lifetime of a building by many years, increase safety from properly maintained equipment, ensure greater comfort and productivity for occupants, and better compliance with efficiency requirements.