Preventive maintenance is a concept that includes care and servicing of equipment for the purpose of keeping equipment in a satisfactory operating condition. It is designed to improve equipment life and avoid any unplanned maintenance activities. This is accomplished through a systematic inspection, detection and correction of any developing failures before they occur. Preventive maintenance is a scheduled activity performed on equipment to prevent its breakdown. The schedule can be based on specified time intervals or certain usage levels. The main goal of any maintenance program is to avoid, or minimize, the consequences of equipment failure.
Unplanned , reactive maintenance has many overhead costs that can be avoided when using a preventive maintenance program. The cost of unplanned maintenance includes lost production, higher costs for parts and shipping, as well as time lost responding to emergencies and diagnosing faults while equipment is not working. When maintenance is planned, each of these costs can be reduced: Equipment can be worked on during planned production downtime; parts, supplies and personnel can be gathered and coordinated to minimize the time necessary to make any repairs. These measures have the ability to decrease the total cost of the maintenance.
Both the FDA and ISO require a company to have some sort of maintenance program in place. According to 21 CFR 820, “Each manufacturer shall establish and maintain schedules for the adjustment, cleaning, and other maintenance of equipment to ensure that manufacturing specifications are met. Maintenance activities, including the date and individual(s) performing the maintenance activities, shall be documented.” There is also the requirement to follow-up on these activities by performing periodic inspections to verify the appropriate procedures and schedules are followed.
Activities that fall within this concept may include, but are not limited to:
- Partial or complete overhauls of equipment at specific intervals
- Oil changes
- Minor adjustments to the equipment
- Changing seals or gaskets before they wear out
- Recording deterioration as it progresses