Engineering

Maintenance, repair and operations or maintenance, repair and overhaul (MRO) is fixing any sort of mechanical or electrical device should it become out of order or broken (repair) as well as performing the routine actions which keep the device in working order (maintenance) or prevent trouble from arising (preventive maintenance).

All actions which have the objective of retaining or restoring an item in or to a state in which it can perform its required function. The actions include the combination of all technical and corresponding administrative, managerial, and supervision actions.

Engineering

In telecommunication, and engineering in general, the term maintenance has the following meanings:

1. Any activity – such as tests, measurements, replacements, adjustments and repairs — intended to retain or restore a functional unit in or to a specified state in which the unit can perform its required functions.^[2]

2. For material — all action taken to retain material in a serviceable condition or to restore it to serviceability. It includes inspection, testing, servicing, classification as to serviceability, repair, rebuilding, and reclamation.^[3]

3. For material — all supply and repair action taken to keep a force in condition to carry out its mission.^[4]

4. For material — the routine recurring work required to keep a facility (plant, building, structure, ground facility, utility system, or other real property) in such condition that it may be continuously used, at its original or designed capacity and efficiency for its intended purpose.^[5]

Manufacturers and Industrial Supply Companies often refer to MRO as opposed to Original Equipment Manufacture (OEM). OEM includes any activity related to the direct manufacture of goods, where MRO refers to any maintenance and repair activity to keep a manufacturing plant running.

Industrial supply companies can generally be sorted into two types:

• the ones who cater to the MRO market generally carry a broad range of items such as fasteners, conveyors, cleaning goods, plumbing, and tools to keep a plant running.
• OEM supply companies generally provide a smaller range of goods in much larger quantities with much lower prices, selling materials that will be regularly consumed in the manufacturing process to create the finished item.