What is operations and maintenance (O&M)?

Updated October 28, 2026 · Reviewed by Israel Margulies, founder and CEO of High Point GPS

Operations and maintenance, or O&M, is everything an organization does to run its equipment and keep it in working order once it is bought and in service: how machines are operated and scheduled, and the routine, preventive, predictive and repair work that keeps them reliable and safe. In practice, an O&M program ties together three things: people with clear roles, a maintenance plan built from the O&M manuals, and records of what was done.

The O&M definition, and what it covers

The US Department of Energy’s O&M Best Practices Guide gives the standard definition: operations and maintenance are the decisions and actions regarding the control and upkeep of property and equipment. It splits them into two groups. The first is control: scheduling, procedures, and work and systems control. The second is performance of routine, preventive, predictive, scheduled and unscheduled actions aimed at preventing failure or decline, with the goal of better efficiency, reliability and safety.

The term comes from facilities and utilities, where an O&M budget pays for running a building or a plant after construction. Equipment fleets use the same idea under other names, such as fleet maintenance or shop operations. Whatever you call it, O&M starts the day a machine goes into service and ends the day you sell or scrap it.

Operations vs maintenance, and what operational maintenance means

Operations is how the equipment is used: who runs it, on which job, for how many hours, at what load, and with which pre-use checks. Maintenance is the work that keeps it able to do that: services, inspections and repairs. Operations wants the machine on the job and maintenance needs it in the shop, so a working O&M program has a weekly schedule both sides agree on before Monday.

Operational maintenance is the part of maintenance done by, or close to, the people who operate the machine: daily checks, greasing, cleaning, topping up fluids and reporting defects. Manufacturing calls this autonomous maintenance. On a fleet, it is the driver’s pre-trip inspection or the operator’s walk-around before starting a loader. Because the operator touches the machine every day, this is where leaks, noises and warning lights get noticed first.

What an operations and maintenance manual contains

Every piece of equipment ships with an O&M manual, sometimes called an operator’s manual or owner’s manual. Caterpillar’s Operation and Maintenance Manuals are a typical layout. The one for its 255 and 265 compact track loaders and 250 and 260 skid steers has a safety section, product information with identification and serial numbers, an operation section, a maintenance section with lubricant viscosities, refill capacities and a maintenance interval schedule, then warranty information and reference material.

For a maintenance team, the maintenance interval schedule is the most valuable page in the book. It lists every task by interval, from the daily checks to the longest service intervals, and it is the starting point for your preventive maintenance plan. Cat’s fluids publication adds the rules for reading it: use the service hour meter, treat calendar intervals as an alternative only when they approximate the hours, service at whichever interval comes first, and shorten intervals in severe, dusty or wet work.

Safety warnings and the location of safety labels on the machine
Identification: model, serial number, engine and component serials
Operating instructions, controls, transport and towing
Maintenance interval schedule, fluid specs and capacities
Warranty terms and what counts as proof of maintenance

Maintenance documents an O&M program should keep

The manual tells you what to do. Your own maintenance documents prove what you did. The DOE guide’s checklist for judging a maintenance system asks whether you can find the last time a system was serviced, by whom and in what condition, and whether O&M procedures, equipment manuals and warranty information are stored where staff can reach them.

For trucks and other commercial motor vehicles, the record is a legal requirement. 49 CFR 396.3 requires motor carriers to keep, for each vehicle, an identification record (company number, make, serial number, year), a means to show the nature and due date of each inspection and maintenance task, and a record of inspections, repairs and maintenance with date and nature. The records stay where the vehicle is housed or maintained for a year, and for six months after the vehicle leaves the carrier’s control.

An asset register: every unit with tag, make, model, serial, meter and location
The maintenance plan: tasks and intervals per machine or category
Procedures and checklists, written in your shop’s words
Work order history: what was done, parts, labor, cost, meter reading
Inspection records with signatures and photos
Warranty dates, registrations and certificates

Why O&M records pay for themselves

The DOE guide tells the story of a federal site whose energy contractor replaced one of two chillers. When both chillers later tripped on high head pressure, the contractor blamed poor operation and maintenance and voided the warranty on the new unit. The site said the system had been commissioned badly. Because the site had kept no O&M records, it had nothing to back its case and kept paying in full.

Equipment fleets meet the same problem in warranty claims, insurance claims after an accident, rental damage disputes and roadside inspections. In each case the question is the same: can you show the service was done on time, with the right parts, by someone qualified? A dated work order with a meter reading, the parts used and the technician’s name answers it.

Measuring an O&M program

The DOE guide lists benchmark metrics drawn from NASA. Use them as targets to discuss, since facility benchmarks don’t always translate to a construction fleet.

Equipment availability: hours available to run at capacity divided by total hours, benchmark above 95 percent
Schedule compliance: hours worked on scheduled jobs divided by hours scheduled, above 90 percent
Emergency maintenance: hours on emergency jobs divided by total hours worked, below 10 percent
Maintenance overtime: overtime hours divided by regular hours, below 5 percent
Preventive maintenance completion: PM actions completed divided by PM actions scheduled, above 90 percent

Running O&M in FleetZap

FleetZap is maintenance management software, so it covers the maintenance half of O&M and the records that link it to operations. Each asset carries tag, make, model, serial, meter, category, location, criticality and warranty dates, with photos and documents such as the O&M manual attached. Schedules built from the manual’s interval chart run by engine hours, miles or days and open work orders when due, each with its procedure. Every job records steps, parts, labor, outside vendor costs and the meter reading at completion.

On the operations side, operators and drivers do daily checks on their phones by scanning a QR label, and anyone can report a problem through the request portal without an account. Status changes are recorded with a reason, so availability and downtime come from real events. Reports cover availability, PM compliance, planned vs reactive work, backlog and cost per machine, and any of them can be emailed on a schedule or exported to CSV.

Key takeaways

Load a new machine's manual and build its PM schedules in the week it arrives, before its first service interval comes up.
If a manual lists both hours and a calendar interval for a task, schedule both; machines that sit still for a season still need the calendar service.
Check one warranty-covered machine a quarter: can you produce every service record its warranty terms ask for in under five minutes?
When emergency hours rise for two months running, look at PM completion on the same machines before adding technicians.

Sources

Frequently asked questions

What is meant by operations and maintenance?

Operations and maintenance means the decisions and actions that control and keep up property and equipment once it is in service. Operations covers how machines are used and scheduled; maintenance covers the routine, preventive, predictive and repair work that keeps them reliable and safe. Together they form the running cost of owning equipment, as opposed to the cost of buying it.

What is an operations and maintenance manual?

An operations and maintenance manual is the document a manufacturer supplies with a machine. It covers safety warnings, identification, how to operate the equipment, a maintenance interval schedule with fluid specs and capacities, and warranty terms. Keep it with the machine, store a copy with the asset record, and build your service schedule from its interval chart.

What is operational maintenance?

Operational maintenance is the basic upkeep done by the people who run the equipment as part of their daily work: pre-use checks, cleaning, greasing, topping up fluids and reporting defects. Manufacturing calls it autonomous maintenance. It catches problems early and frees technicians for services and repairs that need tools, training or specs.

What maintenance documents should I keep for each machine?

Keep the manufacturer’s manual, an asset record with make, model, serial and meter, the maintenance schedule, every work order with date, meter reading, parts and labor, inspection records and warranty papers. Commercial motor vehicles have a legal minimum under 49 CFR 396.3, including records of inspections, repairs and maintenance with their date and nature.

How long should maintenance records be kept?

For commercial motor vehicles, 49 CFR 396.3 requires carriers to keep inspection, repair and maintenance records for one year where the vehicle is housed or maintained, and for six months after it leaves their control. Many fleets keep the full history for the life of the machine, because warranty claims and resale value depend on it.

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