What are the types of maintenance, with examples?
Updated · Reviewed by Israel Margulies, founder and CEO of High Point GPS
The main types of maintenance are reactive (fixing after a failure), preventive (servicing on a time or usage schedule), condition-based and predictive (servicing when measurements show wear), and proactive (removing the causes of failure), with autonomous maintenance describing who does the basic upkeep. A maintenance strategy is the mix of those you choose for each machine, based on what its failure would cost.
The types of maintenance at a glance
Different sources slice the list differently, but the US Department of Energy’s O&M Best Practices Guide and NASA’s reliability-centered maintenance guide use the same core groups. Here they are with an equipment-fleet example of each.
- Reactive or breakdown maintenance: a loader’s alternator fails and gets replaced when it stops charging
- Corrective maintenance: a technician finds a weeping hydraulic fitting at an inspection and books the repair
- Emergency maintenance: a truck’s air brake line ruptures before a run and is fixed before it moves
- Run-to-failure (planned): work lights on a trailer are replaced when they burn out, with spares on the shelf
- Preventive maintenance: an excavator’s engine oil and filters are changed every 500 hours
- Condition-based maintenance: tires are replaced when tread depth reaches the shop’s limit
- Predictive maintenance: oil analysis shows rising wear metals in a final drive, so it is rebuilt before it fails
- Proactive maintenance: after three failures, a chafing hose is rerouted and clamped so it stops failing
- Autonomous maintenance: the operator greases the machine and does the walk-around every morning
Reactive maintenance: breakdown, corrective and emergency
NASA’s guide lists the other names for reactive maintenance: breakdown, repair, fix-when-fail and run-to-failure. Work happens only after the machine’s condition has slipped far enough to cause a functional failure. The DOE guide sets out the trade: reactive maintenance needs less staff and spends nothing up front, but you pay later in unplanned downtime, overtime, secondary damage and a big stock of spares.
Corrective maintenance overlaps with reactive work and is the broader word: any repair that restores a machine after a fault is found, whether it broke on the job or showed up at an inspection. Emergency maintenance is the corrective work that can’t wait. Run-to-failure becomes a deliberate strategy when you choose it ahead of time for cheap, non-critical items, with the spare and the swap planned.
Preventive maintenance: time-based and meter-based
The DOE guide defines preventive maintenance as actions performed on a time-based or machine-run-based schedule that detect, preclude or mitigate degradation, to sustain or extend useful life. For fleets, the run-based version matters most: oil changes every 250 or 500 engine hours, truck services every so many miles, with calendar intervals for things that age whether they run or not, such as annual inspections, batteries and fire extinguishers. Routine maintenance, the daily and weekly checks and greasing, sits inside the preventive program as its most frequent tasks.
Preventive work is predictable, easy to schedule and easy to audit. Its weakness, which the DOE guide lists, is that some of it is unneeded and catastrophic failures still happen, because many failures aren’t tied to age or hours.
Condition-based and predictive maintenance
Condition-based maintenance acts on a measured condition crossing a limit: a tread depth, a brake lining thickness, a coolant temperature, a battery voltage. Predictive maintenance goes a step further and uses the trend in those measurements, often from sensors or lab analysis, to plan the repair before the failure. The DOE guide’s comparison table, drawn from a 2001 study, shows the cost difference per horsepower per year: about $18 for reactive, $13 for preventive and $9 for predictive programs done well. Treat those as relative figures from plant equipment rather than a forecast for your fleet.
For mobile equipment, condition data comes from inspections with recorded readings, oil analysis, and telematics that report engine hours, temperatures, voltages and fault codes. You don’t need a sensor on every bearing to start: readings your technicians already take at a PM, recorded with numbers instead of ticks, count.
Proactive maintenance and RCM
NASA’s guide defines proactive maintenance as the effort to identify, monitor and control future failure, with the emphasis on understanding and removing its cause. It covers better specifications when you buy or rebuild equipment, precision installation, failed-part analysis and root-cause failure analysis, with the goal of fixing the equipment permanently. On a fleet, proactive work looks like rerouting a hose that keeps chafing, changing a supplier after repeat bearing failures, or adding a guard to stop rock damage.
Reliability-centered maintenance (RCM) is the method that decides which type each component gets. The DOE guide sums it up: not all equipment is equally important, different equipment fails in different ways, and resources are limited, so you match the task to the failure. Its $6 per horsepower per year figure for RCM done well sits at the bottom of the same comparison.
What is autonomous maintenance?
Autonomous maintenance is one of the pillars of total productive maintenance (TPM): operators take on the basic care of their own equipment, such as cleaning, inspecting, lubricating and tightening, and report anything abnormal to maintenance. The Japan Institute of Plant Maintenance (JIPM), the Japanese body that promotes TPM, has run a certification for production operators in this work since 2001, aimed at catching failures and quality defects early and finding hidden defects.
For fleets, autonomous maintenance is the operator’s pre-use check and daily grease, done properly with readings and a way to report what they find. It costs little and moves defect detection to the person who sees the machine every day, which leaves technicians the work that needs their skills.
Choosing a maintenance strategy and optimizing the mix
Maintenance optimization means putting each machine on the cheapest type of maintenance that still keeps its failures acceptable. NIST’s study of US manufacturers found an average mix of 45.7 percent reactive, 31.8 percent preventive and 17.3 percent predictive work, and plants in the most reactive quarter had 3.3 times the downtime of those in the least reactive quarter. The DOE guide describes top-performing facilities as under 10 percent reactive, 25 to 35 percent preventive and 45 to 55 percent predictive.
A fleet doesn’t need to copy a plant’s mix. Rank machines by criticality, then pick per machine: run-to-failure for cheap items with spares, meter-based preventive for engines, drivetrains and safety systems, condition checks at inspections for wear items like tires, brakes and undercarriage, telematics alerts on the units where a breakdown costs most, and proactive fixes for anything that fails twice for the same reason. Review the mix once a year against your repair history.
Running a mixed strategy in FleetZap
FleetZap supports each type in one system. Preventive schedules count engine hours, miles or days and open work orders when due. Inspection steps record readings with minimum and maximum limits, and a reading outside them counts as a fail and opens a repair, which gives you condition-based checks without sensors. Optional GPS trackers add fault codes that open work orders and threshold automations on coolant temperature, fuel, battery, speed or meter readings.
Operators do their daily checks on a phone by scanning a QR label, so autonomous maintenance gets recorded. Repairs carry problem, cause and remedy codes, and the failure analysis report shows top problems and repeat offenders, which is where proactive work starts. Reports show planned vs reactive work, PM compliance and MTBF, so you can see the mix you run today.
Key takeaways
- Sort every component on your three most expensive machines as reactive, preventive, condition-based or predictive, or proactive; anything you can't place yet is reactive by default.
- When a run-to-failure item has no spare on the shelf, treat it as an unplanned reactive job and fix the stocking gap.
- Turn the pass/fail inspection items that wear gradually (tread, lining, undercarriage) into number readings with a limit; that is the cheapest condition-based program you can start.
- Put any failure that repeats for the same cause on a proactive list and give each item an owner and a date.
- Recheck the mix yearly against your planned vs reactive hours; if reactive work isn't falling, the preventive schedule needs attention before you buy predictive tools.
Sources
- US DOE FEMP: Operations and Maintenance Best Practices Guide, Release 3.0
- NASA Reliability-Centered Maintenance Guide for Facilities and Collateral Equipment (2008)
- NIST AMS 100-34: Economics of Manufacturing Machinery Maintenance (2020)
- Japan Institute of Plant Maintenance (JIPM): Autonomous Maintenance Specialist certification
FleetZap Maintenance
Work orders, PM, parts, compliance, assets and KPIs. Explore FleetZap Maintenance.
Frequently asked questions
What are the main types of maintenance?
The main types are reactive or breakdown maintenance, corrective maintenance, preventive maintenance on time or usage intervals, condition-based maintenance, predictive maintenance, and proactive maintenance that removes the causes of failure. Reliability-centered maintenance is a method for choosing among them, and autonomous maintenance describes operators taking on basic upkeep of their own machines.
What is proactive maintenance?
Proactive maintenance means finding and removing the causes of failures so they don’t come back, instead of only repairing them. It includes root-cause analysis of repeat failures, better specifications when buying or rebuilding equipment, careful installation and changes such as rerouting a hose or adding a guard. NASA’s maintenance guide describes its goal as fixing the equipment permanently.
What is autonomous maintenance?
Autonomous maintenance is a part of total productive maintenance in which operators carry out basic care of their own equipment: cleaning, inspecting, lubricating, tightening and reporting abnormalities. On an equipment fleet it matches the operator’s daily walk-around and greasing. It catches early signs of trouble and frees technicians for services and repairs that need their skills.
What is a maintenance strategy?
A maintenance strategy is the plan for which type of maintenance each machine or component gets, and why. It is usually based on how critical the machine is, how it fails and what a failure costs. A typical fleet strategy combines meter-based preventive maintenance, condition checks at inspections, run-to-failure for cheap items and root-cause fixes for repeat failures.
How do you optimize maintenance?
Rank your machines by criticality, look at each one’s repair history, and move it to the cheapest maintenance type that keeps its failures acceptable. Shorten intervals where machines fail between services, lengthen them where services find nothing and the manual allows it, and fix repeat failures at the cause. Review planned vs reactive work every quarter.