What is preventive maintenance?

Scheduled work that stops failures before they start.

Preventive maintenance (PM) is work performed on a fixed schedule — time-based, usage-based or seasonal — to keep assets healthy and prevent failures: lubrication routes, inspections, filter changes, overhauls.

PM compliance — the share of planned work completed on time — is the health metric most teams track first. Low compliance means the backlog is growing and failures are being deferred, not prevented.

• How it's measured