Plant maintenance is the service and repair of assets and equipment. During normal operation, assets may accumulate wear-and-tear that needs to be addressed. Deviations outside of normal operation of cause the majority of damage to equipment and assets.

Plant maintenance includes scheduled and unscheduled maintenance. Plant maintenance may be scheduled according to age of equipment or usage of equipment. Unscheduled plant maintenance can occur after equipment failure or operation excursions.

Plant maintenance can cause downtime due to process disruption and critical assets being taken offline for servicing. During plant maintenance, input supply chains may lose efficiency as assets are unable to process at their normal rate. The short-term reduction in profitability caused by process disruption, as well as the costs associated with servicing or repairs, often leads many companies to defer plant maintenance.