Actuarial analysis: Statistical analysis of failure data to determine the age-reliability characteristics of an item.

Asset Management:  the systematic planning and control of a physical resource throughout its life. This may include the specification, design, and construction of the asset, its operation, maintenance and modification while in use, and its disposal when no longer required.

Availability: the proportion of total time that an item of equipment is capable of performing its specified functions, normally expressed as a percentage. It can be calculated by dividing the equipment available hours by the total number of hours in any given period.

Backlog:  It’s work which has not been completed by the nominated ‘required by date’. The period for which each Work Order is overdue is defined as the difference between the current date and the ‘required by date’.

Benchmarking: the process of comparing performance with other organizations, identifying comparatively high performance organizations, and learning what it is they do that allows them to achieve that high level of performance.

Component:  a subassembly of an Asset, usually removable in one piece and interchangeable with other, standard components (eg. Truck engine).

 Computerized Maintenance Management System: It’s a computerized system to assist with the effective and efficient management of maintenance activities through the application of computer technology.

Corrective Maintenance: It’s any maintenance activity which is required to correct a failure that has occurred or is in the process of occurring. This activity may consist of repair, restoration or replacement of components.

Downtime:  the time that an item of equipment is out of service, as a result of equipment failure. The time that an item of equipment is available, but not utilized is generally not included in the calculation of downtime.

Emergency Maintenance Task:  a maintenance task carried out in order to avert an immediate safety or environmental hazard, or to correct a failure with significant economic impact.

Estimated Plant Replacement Value: the estimated cost of capital works required to replace all the existing assets with new assets capable of producing the same quantity and quality of output. This is a key value often used in benchmarking activities.

Failure: an item of equipment has suffered a failure when it is no longer capable of fulfilling one or more of its intended functions. Note that an item does not need to be completely unable to function to have suffered a failure.

Failure Mode: It’s any event which causes a failure.

Functional Failure:  Used in Reliability Centered Maintenance terminology. It’s the inability of an item of equipment to fulfil one or more of its functions. Interchangeably used with Failure.

Gantt Chart:  A bar chart format of scheduled activities showing the duration and sequencing of activities.

Infant Mortality: The relatively high conditional probability of failure during the period immediately after an item returns to service.

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

Maintainability:  the ease and speed with which any maintenance activity can be carried out on an item of equipment. It may be measured by Mean Time to Repair.

Non-Operational Consequences:  a failure has non-operational consequences if the only impact of the failure is the direct cost of the repair.

Outage: a term used in some industries (notably power generation) which is equivalent to a shutdown.

Predictive Maintenance:  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.

Quality Rate:  It’s used in the calculation of Overall Equipment Effectiveness. The proportion of the output from a machine or process which meets required product quality standards. It’s normally specified as a percentage.

Repair: any activity which returns the capability of an asset that has failed to a level of performance equal to, or greater than, that specified by its Functions, but not greater than its original maximum capability.

Run-to-Failure: No Scheduled Maintenance – an Equipment Maintenance Strategy, where no routine maintenance tasks are performed on the equipment.

Scheduled Maintenance: It’s any maintenance work that has been planned and included on an approved Maintenance Schedule.

Total Productive Maintenance: It’s a company-wide equipment management program, with its origins in Japan, emphasizing production operator involvement in equipment maintenance, and continuous improvement approaches.

Unscheduled Maintenance:  It’s any maintenance work that has not been included on an approved Maintenance Schedule prior to its commencement. Uptime – strangely enough, the opposite of downtime. It is defined as being the time that an item of equipment is in service and operating.

Value Engineering: It’s a systematic approach to assessing and analyzing the user’s requirements of a new asset, and ensuring that those requirements are met, but not exceeded. It consists primarily of eliminating perceived “non-value-adding” features of new equipment.