Since PRONTO ESRs come from a variety of backgrounds, they needed a consistent vocabulary. They came out with a PRONTO glossary. We hope others will find it useful.


An alarm gives an audio or visual indication about a problem or condition. In fault detection, an alarm is raised when a fault is detected.

The state of a component, or a network of components, in regards to its working order.

A proactive maintenance task that is performed when the need arises. Usually when one or more indicators show that equipment performance is deteriorating, or predictive indicators show that a failure is soon to occur.

Maintenance task performed to identify, isolate, and rectify a fault so that the equipment can be returned to an operational state.

The process of breaking down represented by a series of detrimental changes in physical condition, caused by time, use or external factors.

The modification of consumer demand (usually for energy) through various methods including financial incentives.

An undesired deviation of a process variable from its desired set point that in turn affects the status of an associated control system.

MPC that considers economics through the use of economic-based objective functions or constraints.

Fault Isolation also known as Root Cause Analysis consist of determining the location(s) or primary cause(s) of a fault.

The permanent termination of a system’s ability to perform its required function under specified operating conditions.

An alarm given about something that fails to happen.

The state of an item characterized by the inability to perform a required function (including unpermitted variable deviations), excluding the inability caused by planned events such as preventative maintenance or due to the lack of external resources.

The process of fault detection consists of determining that a fault is present (when operational conditions deviate from the norm) and the time at which the deviations occurred.

The process of fault detection and isolation.

The process of determining the type and magnitude of a fault.

A prediction of the future conditions of a faulty system (including performance degradation and remaining lifetime) based on the symptoms of said fault.

Feature extraction consists in applying a transformation to the original feature vector. The new features will reflect the underlying relationship existing in original features, highlight some characteristics, and have a reduced dimension if necessary.

Feature selection consists in selecting a small subset of original features, e.g. to focus on some variables or reduce the dimension.

The state of something relative to its desired ideal state. A healthy system is an undegraded system without faults or failures.

A fault that develops gradually over time which is difficult to detect in its early stages.
The average time between failures, measured from the instant a failure was fixed to the time which the next failure occurs.

The average time required to repair a failed component or device.

Predictive maintenance is a condition based maintenance task that predicts when a fault might occur and thus suggests a window in which maintenance should be performed.

The periodic servicing of equipment by personnel for the purpose of maintaining equipment in satisfactory operating condition by providing periodic systematic inspection.

The process of reversing or mitigating the effects of a fault.

In process control, RTO is an online optimization mechanism that provides set-points for lower level controllers; traditionally it is based on steady-state process models.

The reliability of a piece of equipment is the probability of a unit being able to function in accordance with its intended purpose.

An estimate of the amount of remaining time that an item or system is estimated to be able to function in accordance with its intended purpose.

Maintenance strategy where assets are deliberately allowed to operate until they break at which point reactive maintenance is performed. No other maintenance is performed before failure.

A phenomena in which a system evolves over time, as opposed to the steady state of a system.