Ralph Pete Peters Image
Ralph 'Pete' Peters
Founder & President
"Maintenance Excellence Begins with

Become a PRIDE Member and receive our newsletters, maintenance related articles, special discounts offered only to a PRIDE Member, and more. Just click the link below, complete the information and submit. TMEII will always protect your privacy and you can unsubscribe at anytime.

Become a PRIDE Member

Contact Me

Ralph W. 'Pete' Peters
President & Owner
P: 919-270-1173
E: ralphpetepeters@gmail.com


TMEII Sponsor's

The TMEII family is a proud sponsor of Adventurers for Special Needs (AFSN). In fact, Ralph 'Pete' Peters TMEII Founder/President is Co-founder of AFSN with his son, Brian Peters. This organization is near and dear to all of the TMEII family. Learn More

A Reliability & Maintenance Excellence and MRO Glossary


Introduction:The following terms and definitions are from the area of Maintenance Management, Maintenance Storeroom Operations, Inventory Management, and MRO Materials Management areas. In addition we have included Oil and Gas terms. Included in this version are definitions of selected terms used within the entire PRIDE-in-Maintenance.com site.

K    L    M    N    O



Keep Full - Term used for maintaining set levels of shop stock Inventory of Class C Items. (See also Shop Stock)

Key Performance Indicators (KPI) - A select number of key measures that enable performance against targets to be monitored.

Knuckle Buster - A poor quality, imitation, adjustable wrench.

L GoToTopArrow


Last In-First Out (LIFO) - Use newest Inventory next. LIFO accounting values each item used at the cost of the last item added to Inventory. Contrasts with First In-First Out (FIFO).

Lead Time - Allowance made for that amount of time estimated or actually required to accomplish a specific task such as acquiring a part.

Lean - Began as Lean Manufacturing which is often known simply as "Lean", is the optimal way of producing goods and services through the removal of waste and implementing flow, as opposed to batch and queue. Lean is a generic process management philosophy derived mostly from the Toyota Production System renowned for its focus on reduction of the original Toyota seven wastes in order to improve overall customer value. But there are varying perspectives on how this is best achieved to include Lean Maintenance.

Lease - A legal document executed between a mineral owner and a company or individual that conveys the right to
explore for and develop hydrocarbons and/or other products for a specified period of time over a given area.

Ledger Inventory - Items carried on the corporate financial balance sheet as material valued at cost.

Level of Repair (LOR) - Locations and Facilities at which items are to be repaired. Typical levels are operator, field technician, bench, and factory.

Level of Services (stores) - Usually measured as the ratio of Stock Outs to all stores issues.

Life - That strange experience you have all day, every day. In a maintenance context, you may want to look at Equipment Life.

Life Cycle - The series of phases or events that constitute the total existence of anything. The entire "womb to tomb" scenario of a product from the time concept planning is started until the product is finally discarded.

Life Cycle Analysis (LCA) - An analytical methodology used to comprehensively quantify and interpret the environmental flows to and from the environment (including air emissions, water effluents, solid waste and the consumption depletion of energy and other resources) over the life cycle of a product or process. LCAs should be performed in adherence to the International Organization for Standardization (ISO) 14040 series of standards.

Life Cycle Costing - All costs associated with the items of Life Cycle including design, manufacture, operation maintenance and Disposal; a process of estimating and assessing the total costs of ownership, operation and maintenance of an item of equipment during its projected equipment Life. Typically used in comparing alternative equipment design or purchase options in order to select the most appropriate option.

Liquefied Natural Gas (LNG) - Natural gas that has been converted to a liquid by refrigerating it to -260°F. Liquefying natural gas reduces the fuel's volume by 600 times, enabling it to be shipped economically from distant producing areas to markets.

Local Distribution Company (LDC) - A company that delivers natural gas to end users in a geographic area.

Logistics Engineering - The professional art of applying science to the optimum planning, handling, and implementation of personnel, materials, and Facilities, including Life Cycle designs, procurements, production, Maintenance, and supply.

Logistic Support Analysis (LSA) - A methodology for determining the type and quantity of Logistic Support required for a system over its entire Life Cycle. Used to determine the Cost Effectiveness of asset based solutions.

M GoToTopArrow


Main - Gas pipe generally laid along street right-of-ways from which extends smaller lateral service lines to individual customer gas meters.

Maintainability - The inherent characteristic of a design or installation that determines the ease, economy, safety, and accuracy with which Maintenance actions can be performed. In addition, the ability to restore a product to service or to perform Preventive Maintenance within required limits. The rapidity and ease with which maintenance operations can be performed to help prevent malfunctions or correct them if they occur, usually measures as Mean Time to Repair; the ease and speed with which any maintenance activity can be carried out on an item of equipment. Maintainability may be measured by Mean Time to Repair. It is a Function of equipment design, and maintenance task design (including use of appropriate tools, jigs, work platforms etc).

Maintainability Engineering - The application of applied scientific knowledge, methods, and management skills to the development of equipment, systems, projects, or operations that have the inherent ability of being effectively and efficiently maintained; the set of technical processes that apply Maintainability Theory to establish system maintainability Requirements, allocate these requirements down to system elements to predict and verify system maintainability performance.

Maintenance - The Function of keeping items or equipment in, or restoring them to, serviceable condition. It includes: Servicing, Test, Inspection, Adjustment/Alignment, Removal, Replacement, Reinstallation, Troubleshooting, Calibration, Condition Determination, Repair, Modification, Overhaul, Rebuilding and Reclamation. Maintenance includes both corrective and preventive activities. Any activity carried out to retain an item in, or restore it to, an acceptable condition for use or to meet its Functional Standard.

Maintenance as a Business - A philosophy and practice that views the process of maintenance in terms of being Profit-Centered Maintenance and Customer-Centered Maintenance.

Maintenance Engineering - Developing concepts, criteria, and technical requirements for maintenance during the conceptual and acquisition phases of a project. Providing policy guidance for maintenance activities, and exercising technical and management direction and review of maintenance programs. A staff Function intended to ensure maintenance techniques are effective, equipment is designed for optimum Maintainability, that persistent and chronic problems are analyzed, and corrective actions or Modifications are made.

Maintenance Excellence Index (MEI) - An essential Component to The Maintenance Excellence Institute International's implementation of Profit-Centered Maintenance. It is a progressive approach to Performance Measurement within maintenance operations achieved by integrating multiple metrics into a composite Total MEI Value. It includes the comparison of current performance to both the performance goal and baseline value for each metric selected. Ideally suited to measure progress toward Maintenance Excellence across multiple sites within an organization.

Maintenance Leader - Maintenance Managers, Supervisors, Foremen, Maintenance Engineers and Reliability Engineers

Maintenance Policy - A Statement of Principle used to guide maintenance management decision making.

Maintenance Repair Operations (MRO) - A term generally used as MRO items referring to parts, materials, tools and Equipment Used in the maintenance process.

Maintenance Requirements:

  • Inspection - A maintenance requirement when the basic objective is to assure that a Requisite Condition or Quality exists. In order to inspect for the desired condition, it may be necessary to remove the item, to gain access by removing other items, or to disassemble partially the item for inspection purposes. In such cases, these associated actions necessary to accomplish the required inspection would be specific tasks.
  • Troubleshooting - A maintenance operation that involves the Logical Process (series of tasks) which leads to positive Identification, location, and isolation of the cause of a malfunction.
  • Remove - A Maintenance Requirement when the basic objective is to separate the Item from the next higher assembly. This requirement is usually applied for a Configuration Change.
  • Remove and Replace - This requirement constitutes the removal of one item and replacement of it with another like item. Such action can result from a Failure or from a Scheduled Action.
  • Remove and Reinstall - A maintenance requirement when an item is removed for any reason, and the same item's reinstalled.
  • Adjustment/Alignment - A maintenance requirement when the primary cause of the maintenance action is to adjust or align, or to verify adjustment/alignment of specific equipment. Adjustment-Alignment accomplished subsequent to repair of a given item is not considered a separate requirement and is included as a task in the repair requirement.
  • Functional Test - Constitutes a system or subsystem Operational Checkout either as Condition Verification after the accomplishment of Corrective Maintenance Action or as a scheduled requirement on a periodic basis.
  • Conditioning - A maintenance requirement whenever an item is completely disassembled, refurbished, tested and returned to a serviceable condition, meeting all requirements set forth is applicable Specifications. It may result from either a scheduled or unscheduled requirement and is generally accomplished at the depot/factory level of maintenance.

Maintenance Schedule - A comprehensive list of planned maintenance and its sequence of occurrence based on priority in a designated period of time; a list of planned maintenance tasks to be performed during a given time period, together with the expected start times and durations of each of these tasks. Schedules can apply to different time periods (e.g. Daily Schedule, Weekly Schedule etc.).

Maintenance Shut-Down - A period of time during which a plant, department, process, or asset is removed from service specifically for maintenance.

Maintenance Strategy - Principles and strategies for guiding decisions for maintenance management; a long-term plan, covering all aspects of maintenance management which sets the direction for maintenance management, and contains firm action plans for achieving a desired future state for the maintenance Functions.

Maintenance Task Routing File - A computer file containing skills, hours, and descriptions to perform standard maintenance tasks.

Mean Time Between Failures (MTBF) - A measure of equipment reliability, equal to the number of Failures in a given time period, divided by the Total Equipment Uptime in that period.

Mean Time To Repair (MTTR) - A measure of Maintainability, equal to the total equipment Downtime (DT) in a given time period, divided by the number of Failures in that period.

Model Work Order - A Work Order stored in the CMMS that contains all the necessary information required to perform a maintenance task. (See also Standard Job)

Modification - Change in Configuration; any activity carried out on an asset which increases the capability of that asset to perform its Required Functions.

Modularization - Separation of Component of a product or equipment into physically and functionally distinct entities to facilitate Identification, removal, and replacement unitization.

Most Valuable People (MVP) - Your Crafts People and Your Storeroom staff!

MRO Materials Management - The overall management of the process for Requisitioning, Storage/Warehousing, Purchasing, Inventory Management and issue of MRO type items used in the maintenance process.

N GoToTopArrow


Natural Gas - Naturally occurring hydrocarbon gases found in porous rock formations. Its principal component is usually methane. Nonhydrocarbon gases such as carbon dioxide and hydrogen sulfide can sometimes be present in natural gas.

Natural Gas Liquids (NGLs) - General term for highly volatile liquid products separated from natural gas in a gas processing plant. NGLs include ethane, propane, butane and condensate.

Natural Gas Vehicle (NVG ) - General term for highly volatile liquid products separated from natural gas in a gas processing plant. NGLs include ethane, propane, butane and condensate..

Net Acres - The percentage a company owns in an acreage position with multiple owners. For example, a company that has a 50% interest in a lease covering 10,000 acres owns 5,000 net acres.

Non-Destructive Testing (NDT) - Non-destructive testing of equipment to detect abnormalities in physical, chemical or electrical characteristics, using such technologies as Ultrasonic (thickness), Liquid Dye penetrates (cracks), X-ray (weld discontinuities), and Voltage Generators (Resistance).

Non-Operational Consequences - A Failure has non-operational consequences if the only impact of the failure is the direct cost of the repair (plus any secondary damage caused to other equipment because of the failure.

Non-Repairable - Parts or items discarded upon Failure for technical or economic reasons.

Non-Routine Maintenance - Maintenance performed at irregular intervals, with each job unique, and based on Inspection, Failure, or condition; Any maintenance task which is not performed at a regular, Pre-Determined Frequency.

No Scheduled Maintenance - An equipment maintenance strategy, where no Routine Maintenance Tasks are performed on the equipment. The only maintenance performed on the equipment is Corrective Maintenance, and then only after the equipment has suffered a Failure. Also described as a Run-To-Failure Strategy.

O GoToTopArrow


Obsolescence - Decrease in value or use of items that have been superseded by superior items.

Obsolete - Designation of an item for which there is no replacement. The part has probably become unnecessary because of design change.

Oil Sands - Geologic formation comprised predominantly of sand grains and bitumen, a highly viscous form of crude oil.

On-Condition Task - A periodic or continuous inspection designed to detect a potential failure condition prior to functional failure. If the inspection reveals a potential failure condition, corrective action must be taken. If potential failure condition does not exist, nothing is done, item continues in service.

One Million Barrels (MMBBL) - One million barrels of crude oil, bitumen, condensate or natural gas liquids.

One Million Cubic Feet (MMCF) - In the United States, standard conditions are defined as gas at 14.7 psia and 60oF.

One Thousand Cubic Feet (MCF) - A common volumetric unit of measurement for natural gas. 1 - MCF has about 1 million BTUs in it, when natural gas has about 1,000 BTUs per cubic foot.

Operating Context - The operational situation within which an asset operates. For example, is it a stand-alone piece of plant equipment, or is it one of a duty-standby pair? Is it part of a Batch Manufacturing Process or a Continuous Production Process? What is the impact of Failure of this item of equipment on the remainder of the production process? The Equipment Maintenance Strategies for any asset.

Operating Hours - The length of time that an item of equipment is actually operating.

Operational Consequences - A Failure has Operational Consequences if it has a direct adverse impact on operational capability (lost production, increased production costs, loss of product quality, or reduced customer service).

Operational Efficiency - Used in the calculation of Overall Equipment Effectiveness. The actual output produced from an asset in a given time period divided by the output that would have been produced from that asset in that period, had it produced at its rated capacity. Normally expressed as a percentage.

Operator - The entity responsible for managing operations in a field or undeveloped acreage position.

Operator-Based Maintenance (OBM) - A Maintenance Excellence Strategy where equipment or process operators are trained and accountable for selected maintenance tasks. See Autonomous Maintenance.

Order Point - Quantity of parts at which an order will be placed when usage reduces stock to that level; also called Reorder Point (ROP).

Order Quantity - Number of items demanded. The Economic Order Quantity (EOQ), also called Minimum Cost Quantity, is a specific number; but the actual order quantity may vary because of cost, transportation, discounts, or extraordinary demand.

Outage - Term used in some industries, for example, Electrical Power Distribution, to denote when an item or system is not in use.

Overall Craft Effectiveness (OCE) - The OCE Factor is a method developed by the staff of TMEII to measure Craft Labor Productivity that combines three key elements; Craft Utilization (CU) , Craft Performance (CP) and craft methods and quality. Typically, the OCE Factor is determined by only the two elements; % Craft Utilization (CU) x Craft Performance (CP). Compares to OEE in basic concepts but applies directly to productivity of craft labor Assets.

Overall Equipment Effectiveness (OEE) - The OEE Factor is a method to measure overall equipment effectiveness that originated with Japan's Total Productive Maintenance (TPM) strategy for Maintenance Improvement. The OEE Factor combines three key elements; equipment Availability, performance and quality measurement into a common metric that reflect key elements of the manufacturing environment. The OEE Factor equals % Availability x % Performance x % Quality. Compares to OCE in basic concept but applies directly to the Productivity of Physical Assets.

Overhaul - A comprehensive Examination and restoration of an item to an acceptable condition.