Glossary of Terms


A workplace organization methodology centered around five Japanese words which start with the letter S. The Japanese words (and their English transliterated versions) are: seiri (sorting), seiton (straighten or set in order), seiso (sweeping or shining), seiketsu (standardizing) and shitsuke (sustaining).


Acoustic Ultrasound
A predictive maintenance technology that is applied to thickness, density, flow and level sensing. It is associated with the measurement of sound above 15 kHz.
A visual management tool and component of the lean philosophy. These are lights placed on or adjacent to machines or production lines to indicate operation status.
Annual Maintenance Cost
A metric determined by taking the amount of money spent annually to maintain assets divided by the replacement asset value (RAV) of the assets being maintained. It is expressed as a percentage.
Asset Management
A process that oversees the cradle-to-grave status of key plant-floor machinery. It involves the acquisition of such equipment, along with their use, function and ultimate disposal, in order to maximize their potential performance and longevity.
Asset Utilization
A metric determined by multipling Availability x Rate x Quality.
Autonomous Maintenance
Maintenance that is performed by the machine operator / operations crew / production department rather than the maintenance staff. It generally includes tasks such as lubricating and tightening machine parts, and changing filters or belts.
The ratio of the total time that a functional unit is capable of being used during a given interval.


A continuous process where a company measures and compares its functions, systems and practices against those of another entity. In doing so, it can identify gaps in its performance, quality, throughput, etc., and develop game plans to close the gaps.
Best Practice
A process, technique or innovative use of resources that has a proven record of success in providing significant improvement in cost, schedule, quality, performance, safety, environment or other measurable factors that impact the health of an organization.


For computerized maintenance management system. A software package that houses a database of information related to an organization's maintenance operations and functions. Its functionality is tied to scheduling, tracking and monitoring departmental activities and providing a historical overview of cost, budgetary, inventory and personnel data.
Condition Monitoring
A component of predictive maintenance, it is the process of examining parameters of machinery health in order to identify the onset of developing failure. A deviation from a reference value triggers specified actions. Maintenance is scheduled or actions taken to avoid the consequence of failure before it occurs.
Continuous Improvement
A structured, measurement-driven process that continually reviews and improves performance. Actions are taken to eliminate waste and anything that is deemed to be non-value-added. It is a key tenet of lean manufacturing and the Toyota Production System.
Cost of Quality
The costs that are generated as a result of producing defective material.


Desiccant Breather
A device that incorporates a high capture-efficiency filter to help sustain desired cleanliness levels by removing minute particulate matter and by creating low relative humidity levels in the headspace, making condensation and absorption by the lubricant unlikely. When a system is properly fitted with a breather containing drying and filtration media, the contaminant ingression is greatly reduced.
Design for Manufacturing
A methodology that seeks to simplify a current or a future product design and/or manufacturing process in order to achieve cost savings.
Design for Six Sigma
DFSS is an approach used to design or redesign a product or service from the ground up, building in high levels of quality, reliability and performance.
A methodology that incorporates the following five steps: Define the project goals and customer requirements. Measure the process to determine current performance. Analyze and determine the root cause(s) of the defects. Improve the process by eliminating defect root causes. Control future process performance.


Failure Modes and Effects Analysis (FMEA)
It is a disciplined approach used to identify possible failures of a product or service and then determine the frequency and impact of the failure.
Food Grade Lubricant
Lubricants acceptable for use in meat, poultry and other food processing equipment, applications and plants. The lubricant types in food-grade applications are broken into categories based on the likelihood they will contact food. The USDA created the original food-grade designations H1, H2 and H3, which is the current terminology used. The approval and registration of a new lubricant into one of these categories depends on the ingredients used in the formulation.


Gas Turbine
An engine that uses the energy of expanding gases passing through a multi-stage turbine to create rotating power.
Grease Fitting
A small fitting which connects a grease gun and the component to be lubricated. The fitting is installed by a threaded connection, leaving a nipple to which the grease gun attaches.
Grease Gun
A tool (normally hand-powered) which is used for lubrication tasks. By squeezing the trigger of the gun, grease is applied through an aperture to a specific point.


H1 Lubricant
Food-grade lubricants used in food processing environments where there is some possibility of incidental food contact. Lubricant formulations may only be composed of one or more approved basestocks, additives and thickeners (if grease) listed in Guidelines of Security Code of Federal Regulations (CFR) Title 21, §178.3570.
H2 Lubricant
Lubricants used on equipment and machine parts in locations where there is no possibility that the lubricant or lubricated surface contacts food. Because there is not the risk of contacting food, these lubricants do not have a defined list of acceptable ingredients. They cannot, however, contain intentionally heavy metals such as antimony, arsenic, cadmium, lead, mercury or selenium. Also, the ingredients must not include substances that are carcinogens, mutagens, teratogens or mineral acids.
H3 Lubricant
Also known as soluble or edible oil. These are used to clean and prevent rust on hooks, trolleys and similar equipment.
Helical Gear
A cylindrical gear wheel which has slanted teeth that follow the pitch surface in a helical manner.
An acronym for heating, ventilation and air conditioning; these are among the key systems managed by facilities maintenance professionals.
Hybrid Bearing
A bearing that consists of metal rings and ceramic balls.
Hydro Turbine
A rotary engine whose energy is generated from moving water.


Infrared Thermography
A predictive maintenance technology that involves the estimation of surface temperatures by analyzing the emitted infrared radiation. Thermographic cameras detect radiation in the infrared range of the electromagnetic spectrum (around 900 to 14,000 nanometers or 0.9 to 14 µm) and produce images of that radiation.
Inventory Management
The formal management of the timing and quantities of goods to be ordered and stocked by an organization in order that demand can always be satisfied without excess expenditure.


Also known as JIT. It is an inventory strategy that is employed to increase efficiency and decrease waste by receiving goods only as they are needed.


A Japanese term that has been adopted into English over the past two decades. It refers to a philosophy or practices focusing on continuous improvement in manufacturing activities, business activities in general, and even life in general. The object is to continually seek perfection and to remove waste.


Lean Manufacturing
Also known simply as "lean", it is a philosophy that considers the expenditure of resources for any goal other than the creation of value for the end customer to be wasteful, and thus a target for elimination. The seven wastes that are targeted by lean are: overproduction, unnecessary transportation, inventory, motion, defects, over-processing and waiting. The tools, techniques and practices are derived from the Toyota Production System.
Also referred to as LOTO. It is a safety procedure to ensure that dangerous machines are properly shut off and not started again prior to the completion of maintenance work. It requires that power sources be "isolated and rendered inoperative" before any repair procedure is started. LOTO works in conjunction with a lock usually locking the device or the power source with the hasp, and placing it in such a position that no hazardous power sources can be turned on. The procedure requires that a tag be affixed to the locked device indicating that it should not be turned on.
Lubrication System
Components that work together in order to distribute oil between the moving parts of machinery and keep them from rubbing together.


Manufacturing Process
The sequence of operations that are necessary to complete the manufacturing of a part or product.
Mean Time Between Failures (MTBF)
An average time between machinery breakdowns.
Mean Time To Repair (MTTR)
After a machinery breakdown, it is the average time to repair that machine back to acceptable operating conditions.
Mechanical Seal
A device which works to join together systems or mechanisms in order to prevent leakage, contain pressure or exclude contamination.
Things to measure in order to better understand performance levels.
Motor Bearing
A bearing which supports the crankshaft in an internal-combustion engine. It is a support or guide by means of which a moving part is positioned with respect to the other parts of a mechanism.
A Japanese term for something that is wasteful, unproductive and does not add value.


An ancient pump thought to be the world's first sophisticated machine.


Oil Filter
A device which removes the inherent or introduced impurities from the oil that lubricates an internal-combustion engine.
Oil Flushing
A fluid circulation process that is designed to remove contamination and decomposition from a lubrication-based system.
Oil Mist
A method of lubricant delivery in which oil is piped throughout the machine to desired locations and dispensed with a spray nozzle. Oil mist systems are employed to cool and lubricate many machine parts at once.
Oil Mist Lubrication
A method of lubricant delivery in which oil is piped throughout the machine to desired locations and dispensed with a spray nozzle. Oil mist systems are employed to cool and lubricate many machine parts at once.
Oil Mist System
A device which delivers lubricant to multiple machine parts at once via a setup that includes piping and a spray nozzle.
Oil Sampling
A procedure which involves the collection of a volume of fluid from lubricated or hydraulic machinery for the purpose of performing oil analysis. Samples are typically drawn into a clean bottle which is sealed and sent to a laboratory for analytical work.
Operator-Driven Reliability
Also known as Total Productive Maintenance or autonomous maintenance. It is maintenance tasks that are performed by the machine operator / operations crew / production department rather than the maintenance staff. It generally includes tasks such as lubricating and tightening machine parts, and changing filters or belts.
Overall Equipment Effectiveness (OEE)
Also known as OEE. It is a method of measuring productivity performance. More specifically, it is a statistical metric to determine how efficient a machine is running. You calculate it by multiplying a machine’s efficiency, quality and availability. The combination is the value a machine contributes to the production process.


Pareto Principle
A business principle that holds that 80% of the impact of a problem will show up in 20% of its causes.
People Management
The utilization of human resources in order to achieve the organization’s objectives.
Pitch Line
An imaginary line that divides the upper and lower halves of gear teeth while in the contact area.
Plain Bearing
A relatively simple and inexpensive bearing typically made of two parts. A rotary plain bearing can be just a shaft running through a hole. A simple linear bearing can be a pair of flat surfaces designed to allow motion.
Planned Maintenance
Work can be completed with the least interruption to operations and the most efficient use of maintenance resources.
Poka Yoke
It is a Japanese term which translates roughly to mistake proofing. It is a manufacturing technique of preventing errors from occurring by designing the manufacturing process, equipment and tools in such a way that an operation literally cannot be performed incorrectly.
Power Circuit Fault Zone
The system of conductors and connections running from the point of origin of testing to connections at the motor.
Predictive Maintenance (PdM)
An equipment maintenance strategy based on measuring the condition of equipment in order to assess whether it will fail during some future period, and then taking appropriate action to avoid the consequences of that failure. Equipment condition can be measured through a variety of methods, including condition monitoring technologies/techniques, statistical process control or through the human senses.
Preventive Maintenance (PM)
An equipment maintenance strategy that is based on replacing, overhauling, repairing or remanufacturing an item at a fixed interval, regardless of its condition at the time. The impetus is to perform the work as a way to avert mechanical failures and avoid unscheduled downtime.
Preventive Maintenance Optimization (PMO)
A methodology which focuses on improving maintenance effectiveness and efficiency through the review and/or rationalization of programs or tasks. Through such work, from one-third to two-thirds of planned maintenance procedures can be eliminated or combined.
Proactive Maintenance
A key measure of maintenance effectiveness. It is the sum of all maintenance work that is completed to avoid failures or to identify defects that could lead to failures. It includes routine preventive and predictive maintenance activities and work tasks identified from those tasks.
The ratio of measured outputs over measured inputs.


Quality Assurance
A set of activities or processes that are designed to ensure that products, goods and/or services satisfy the requirements of customers in a systematic and reliable fashion.
Quality Control
Measures such as inspection, testing and engineering which are used to oversee and positively influence quality.


The probability that something (a machine, a production line, etc.) will adequately perform its specified and desired purpose for a specific period of time.
Reliability Engineering
Deals with the longevity and dependability of parts, products and systems. More specifically it is about controlling risk. It incorporates a wide variety of analytical techniques designed to help engineers understand the failure modes and patterns of parts, products and systems.
Reliability-Centered Maintenance (RCM)
A structured process, originally developed in the airline industry, to determine the equipment maintenance strategies required for any physical asset to ensure that it continues to fulfill its intended functions in its present operating context. The assets are decomposed, extensively analyzed and described, failure modes and effects analyses (FMEA) are made for the most critical components, and the maintenance organization and processes are carefully (re)defined.
Replacement Asset Value (RAV)
Also referred to as estimated replacement value (ERV). This is the dollar value that would be required to replace the production capability of the present assets in the plant.
Return on Investment (ROI)
A measure of the financial gain (or loss) of a project in relation to its cost. It is calculating by taking: Financial Gain or Loss – Project Cost / Project Cost) X 100.
Return on Net Assets
RONA simply calculates how well a company converts assets to sales, and therefore income. (The simple calculation is sales minus expenses divided by net assets.)
Rolling Element Bearing
A friction-reducing bearing that consists of a ring-shaped track that contains free-revolving metal balls. A rotating shaft or other part turns against such a bearing.
Root Cause
A source or origin of an event, failure or defect.
Root Cause Analysis
Also referred to as RCA. It is a series of problem-solving methods or actions that are aimed at determining the base reason(s) for problems or failure. The stewardship of this process is usually a function of reliability engineering.
Rotating Equipment
Equipment that moves liquids, solids or gases through a system of drivers (turbines, motors, engines), driven components (compressors, pumps), transmission devices (gears, clutches, couplings) and auxiliary equipment (lube and seal systems, cooling systems, buffer gas systems).


Sealed Motor Bearing
These bearings have rubbing seals that seal against recesses in the inner ring shoulder. They are lubricated for life. Under extreme conditions, their life can be short.
A device that is uesd to detect the value (or the change of value) of a physical quantity or parameter and then converts that value into a signal for an indicating or recording instrument.
Seven Wastes
Taken from the Toyota Production System, these are non-value-added activities that should be reduced and/or eliminated. The seven wastes are: overproduction, unnecessary transportation, inventory, motion, defects, over-processing and waiting.
Single Minute Exchange of Dies (SMED)
A lean tool whose procedures aim to reduce changeover time.
Six Sigma
A business management strategy and measure of quality that strives for near perfection. It employs a data-driven methodology for identifying and eliminating defects in products and processes. Achievement of Six Sigma generally denotes a failure rate of 3.4 parts per million opportunities, or 99.9997% perfection. The philosophy was originally implemented by Motorola.
Skilled Labor
Labor with a high level of skill or human capital.
Spur Gear
This is the simplest variation of gear. It consists of a cylinder or disk, with the teeth projecting radially. Each tooth edge is straight and aligned parallel to the axis of rotation. Such gears can be meshed together correctly only if they are fitted to parallel axles.
Standard Work
The most efficient method to perform a task, broken down into elements which are sequenced, organized and repeatedly followed.
Steam Turbine
A mechanical device that extracts thermal energy from pressurized steam. The energy is converted into a rotary motion that drives a device.
Supply Chain
The system of organizations, people, technologies, activities, information and resources that are involved in moving (or transforming) a product or service from its basic form to its finished or end form.


Takt Time
The rate that a completed product needs to be finished in order to meet customer demand.
Output or production measured over a period of time.
A rotary or turning force.
Total Productive Maintenance (TPM)
Also known as autonomous maintenance or operator-driven reliability. It is maintenance tasks that are performed by the machine operator / operations crew / production department rather than the maintenance staff. It generally includes tasks such as lubricating and tightening machine parts, and changing filters or belts.
Total Quality Management (TQM)
Also referred to as TQM. It is a philosophy that embraces all activities through which the needs and expectations of the customer (both internal and external) and the community, and the objectives of the organization, are satisfied in the most efficient and cost-effective way possible by maximizing the potential of all employees in a continuous drive for improvement.
Toyota Production System
Toyota’s vehicle production system is sometimes referred to as a "lean manufacturing system" or a "just-in-time (JIT) system," and has come to be well known and studied worldwide. This production control system has been established based on many years of continuous improvements, with the objective of "making the vehicles ordered by customers in the quickest and most efficient way, in order to deliver the vehicles as quickly as possible." TPS was established based on two concepts. The first is called "jidoka"(loosely translated as "automation with a human touch"), which means that when a problem occurs, the equipment stops immediately, preventing defective products from being produced. The second is the concept of JIT, in which each process produces only what is needed by the next process in a continuous flow.
Training Within Industry
Also referred to as TWI. It is a program which uses a learn-by-doing approach, teaching essential skills for supervisors and team leaders. Its four core elements are: Job Relations, Job Instruction and Job Methods. Its roots go back to the Training Within Industry service created by the U.S. Department of War in 1940.


The period of time in which a machine, production line or plant is functioning and available for use. As a metric, it is defined as Operating Time divided by Scheduled Time.


Value Stream Mapping
A lean exercise used to help participants see and understand the flow of material and information through the value stream.
Vibration Analysis
A predictive maintenance technology that is used to analyze the changes in vibration response, critical speeds and machinery stability vs. an established baseline. It is a useful tool to identify unbalance, misalignment, eccentricity, bent shaft, shaft crack, mechanical looseness, journal bearing faults, rolling element bearing faults, rotor rub, cavitation, electrical motor problems and gear faults.
Visual Workplace
A work environment that is clean, well organized and efficient. It is a key element of lean manufacturing. Organization involves the use of photographs and signage to convey information related to standard work instructions, safety instructions and maintenance procedures.


Weibull Distribution (or Weibull analysis)
Originally developed by Wallodi Weibull, a Swedish mathematician, Weibull analysis is a versatile distribution employed by reliability engineers. While it is called a distribution, it is actually a tool that enables the reliability engineer to first characterize the probability density function (failure frequency distribution) of a set of failure data to characterize the failures as early life, constant (exponential) or wear out (Gaussian or log normal) by plotting time to failure data on a special plotting paper with the log of the times/cycles/miles to failure plotted on a log scaled X-axis vs. the cumulative percent of the population represented by each failure on a log-log scaled Y-axis.
Workplace Safety
A responsibility for ensuring the health and well-being of the populace of a workplace. This populace includes company employees, on-site workers not employed by the company, vendors, visitors, etc.
Worm Gear
A gear that is in the form of a screw. The screw thread engages the teeth on a worm wheel. When rotated, the worm pulls or pushes the wheel, causing rotation.