Maintenance, repair, and operations (
MRO) or
maintenance, repair, and overhaul involves fixing any sort of
mechanicalA machine manages power to accomplish a task, examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work...
or electrical
deviceA machine manages power to accomplish a task, examples include, a mechanical system, a computing system, an electronic system, and a molecular machine. In common usage, the meaning is that of a device having parts that perform or assist in performing any type of work...
should it become out of order or broken (known as repair, unscheduled or casualty maintenance). It also includes performing routine actions which keep the device in working order (known as
scheduled maintenanceAircraft maintenance is the overhaul, repair, inspection or modification of an aircraft or aircraft component.Maintenance includes the installation or removal of a component from an aircraft or aircraft subassembly, but does not include:...
) or prevent trouble from arising (
preventive maintenancePreventive maintenance has the following meanings:#The care and servicing by personnel for the purpose of maintaining equipment and facilities in satisfactory operating condition by providing for systematic inspection, detection, and correction of incipient failures either before they occur or...
). MRO may be defined as, "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."
MRO operations can be categorised by whether the product remains the property of the customer, i.e. a service is being offered, or whether the product is bought by the reprocessing organisation and sold to any customer wishing to make the purchase. (Guadette, 2002)
The former of these represents a closed loop
supply chainA supply chain is a system of organizations, people, technology, activities, information and resources involved in moving a product or service from supplier to customer. Supply chain activities transform natural resources, raw materials and components into a finished product that is delivered to...
and usually has the scope of maintenance, repair or
overhaulOverhaul may refer to:*Overhaul , a Transformers character*The process of overhauling...
of the product. The latter of the categorisations is an open loop supply chain and is typified by refurbishment and remanufacture.
The main characteristic of the closed loop system is that the demand for a product is matched with the supply of a used product. Neglecting asset write-offs and exceptional activities the total population of the product between the customer and the service provider remains constant
Engineering
In
telecommunicationTelecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...
, and
engineeringEngineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
in general, the term maintenance has the following meanings:
- 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.
- 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.
- For material — all supply and repair action taken to keep a force in condition to carry out its mission.
- For material — the routine recurring work required to keep a facility (plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
, building, structure, groundGround may refer to:* Earth's surface* Soil, a mixture of clay, sand and organic matter present on the surface of the Earth and serving as substrate for plant growth and micro-organisms development...
facility, utility systemSystem is a set of interacting or interdependent components forming an integrated whole....
, 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.
Manufacturers and Industrial Supply Companies often refer to MRO as opposed to Original Equipment Manufacture (
OEMAn original equipment manufacturer, or OEM, manufactures products or components that are purchased by a company and retailed under that purchasing company's brand name. OEM refers to the company that originally manufactured the product. When referring to automotive parts, OEM designates a...
). 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.
Maintenance types
Generally speaking, there are two types of maintenance in use:
- Preventive maintenance
Preventive maintenance has the following meanings:#The care and servicing by personnel for the purpose of maintaining equipment and facilities in satisfactory operating condition by providing for systematic inspection, detection, and correction of incipient failures either before they occur or...
, where equipment is maintained before break down occurs. This type of maintenance has many different variations and is subject of various researches to determine best and most efficient way to maintain equipment. Recent studies have shown that Preventive maintenance is effective in preventing age related failures of the equipment. For random failure patterns which amount to 80% of the failure patterns, condition monitoring proves to be effective.
- Corrective maintenance
Corrective maintenance can be defined as a maintenance task performed to identify, isolate, and rectify a fault so that the failed equipment, machine, or system can be restored to an operational condition within the tolerances or limits established for in-service operations...
, where equipment is maintained after break down. This maintenance is often most expensive because worn equipment can damage other parts and cause multiple damage.
Preventive maintenance
Preventive maintenance is maintenance performed in an attempt to avoid failures, unnecessary production loss and safety violations. As equipment cannot be maintained at all times, some way is needed to decide when it is proper to perform maintenance. Normally, this is done by deciding some inspection/maintenance intervals, and sticking to this interval more or less affected by what you find during these activities. The result of this is that most of the maintenance performed is unnecessary; it even adds substantial wear to the equipment. Also, you have no guarantee that the equipment will continue to work even if you are maintaining it according to the maintenance plan.
The effectiveness of a preventive maintenance schedule depends on the
RCM analysisReliability Centered Maintenance, often known as RCM, is a process to ensure that assets continue to do what their users require in their present operating context....
which it was based on, and the ground rules used for cost-effectivity.
Corrective maintenance
Corrective maintenance is probably the most commonly used approach, but it is easy to see its limitations. When equipment fails, it often leads to downtime in production. In most cases this is costly business. Also, if the equipment needs to be replaced, the cost of replacing it alone can be substantial. It is also important to consider health, safety and environment (HSE) issues related to malfunctioning equipment.
Corrective maintenance can be defined as the maintenance which is required when an item has failed or worn out, to bring it back to working order. Corrective maintenance is carried out on all items where the consequences of failure or wearing out are not significant and the cost of this maintenance is not greater than
preventive maintenancePreventive maintenance has the following meanings:#The care and servicing by personnel for the purpose of maintaining equipment and facilities in satisfactory operating condition by providing for systematic inspection, detection, and correction of incipient failures either before they occur or...
.
MRO software
In many organizations because of the number of devices or products that need to be maintained or the complexity of systems, there is a need to manage the information with software packages. This is particularly the case in aerospace (e.g. airline fleets), military installations, large plants (e.g. manufacturing, power generation, petrochemical) and ships.
These software tools help engineers and technicians in increasing the
system availabilityIn telecommunications and reliability theory, the term availability has the following meanings:* The degree to which a system, subsystem, or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at an unknown, i.e., a random, time...
and reducing costs and repair times as well as reducing material supply time and increasing material availability by improving supply chain communication.
As MRO involves working with an organization’s products, resources, suppliers and customers, MRO packages have to interface with many enterprise
business softwareThis article is about software made for business, if you were looking for the business of selling software, see Software business.Business software is generally any software program that helps a business increase productivity or measure their productivity...
systems (
PLMIn industry, product lifecycle management is the process of managing the entire lifecycle of a product from its conception, through design and manufacture, to service and disposal...
,
EAMEnterprise asset management means the whole life optimal management of the physical assets of an organization to maximize value. It covers such things as the design, construction, commissioning, operations, maintenance and decommissioning/replacement of plant, equipment and facilities...
,
ERPEnterprise resource planning systems integrate internal and external management information across an entire organization, embracing finance/accounting, manufacturing, sales and service, customer relationship management, etc. ERP systems automate this activity with an integrated software application...
,
SCMSupply chain management is the management of a network of interconnected businesses involved in the ultimate provision of product and service packages required by end customers...
,
CRMCustomer relationship management is a widely implemented strategy for managing a company’s interactions with customers, clients and sales prospects. It involves using technology to organize, automate, and synchronize business processes—principally sales activities, but also those for marketing,...
).
One of the functions of such software is the configuration of
bills of materialsA bill of materials is a list of the raw materials, sub-assemblies, intermediate assemblies, sub-components, components, parts and the quantities of each needed to manufacture an end product...
or BOMs, taking the component parts list from engineering (eBOM) and manufacturing (mBOM) and updating it from “as delivered” through “as maintained” to “as used”.
Another function is project planning
logisticsLogistics is the management of the flow of goods between the point of origin and the point of destination in order to meet the requirements of customers or corporations. Logistics involves the integration of information, transportation, inventory, warehousing, material handling, and packaging, and...
, for example identifying the
critical pathThe critical path method is an algorithm for scheduling a set of project activities. It is an important tool for effective project management.-History:...
on the list of tasks to be carried out (inspection, diagnosis, locate/order parts and service) to calculate turnaround times (TAT).
Other tasks that software can perform:
- Planning operations,
- Managing execution of events,
- Management of assets (parts, tools and equipment inventories),
- Knowledge-base data on:
- Maintenance service history,
- Serial number
A serial number is a unique number assigned for identification which varies from its successor or predecessor by a fixed discrete integer value...
ed parts,
- Reliability data: MTBF, MTTB (mean time to breakdown), MTBR (mean time between removals),
- Maintenance and repair documentation and best practices,
- Warranty/guarantee documents.
Many of these tasks are addressed in
Computerized Maintenance Management SystemComputerized maintenance management system is also known as enterprise asset management and computerized maintenance management information system ....
s (CMMS). Data standards have been developed around these activities, most notably EAMXML and
MIMOSAMIMOSA is a Czech scientific microsatellite. The satellite is nearly spherical with 28 sides and carries a microaccelerometer to monitor the atmospheric density profile by sensing the atmospheric drag on the approximated sphere. It has a fairly eccentric orbit, with an initial perigee of...
.
MRO goods
MRO goods are typically defined as any goods used in the creation of a product but not in the final product itself. Examples include:
- the machinery used to make a product
- spare part
Spare Parts may also refer to:* Spare Parts , by Status Quo* Spare Parts is a Doctor Who audio drama.* Spare Parts , by Servotron* "Spare Parts" , by Bruce Springsteen* "Spare Parts"...
s for the machinery that creates the product, and
- items used to maintain the facility in which the product is made.
See also
- Aircraft maintenance
Aircraft maintenance is the overhaul, repair, inspection or modification of an aircraft or aircraft component.Maintenance includes the installation or removal of a component from an aircraft or aircraft subassembly, but does not include:...
- Auto maintenance
- Darning
Darning is a sewing technique for repairing holes or worn areas in fabric or knitting using needle and thread alone. It is often done by hand, but it is also possible to darn with a sewing machine...
- Logistics center
A logistics center is a facility dedicated to logistical operations. A logistics center might be a warehouse, freight forwarder, or a repair depot....
- Product Lifecycle Management
In industry, product lifecycle management is the process of managing the entire lifecycle of a product from its conception, through design and manufacture, to service and disposal...
- Reliability centered maintenance
Reliability Centered Maintenance, often known as RCM, is a process to ensure that assets continue to do what their users require in their present operating context....
- Reliability engineering
Reliability engineering is an engineering field, that deals with the study, evaluation, and life-cycle management of reliability: the ability of a system or component to perform its required functions under stated conditions for a specified period of time. It is often measured as a probability of...
- Remanufacturing
Remanufacturing is the process of disassembly and recovery at the module level and, eventually, at the component level. It requires the repair or replacement of worn out or obsolete components and modules. Parts subject to degradation affecting the performance or the expected life of the whole are...
- Scheduled maintenance
- User reengineering
User reengineering is the redesign of a product, not for resale, but by a consumer or user. Historically, concept and craft were often more significant components of products as they were intended to last indefinitely...