Optimal maintenance
Encyclopedia
Optimal maintenance is the discipline within operations research
concerned with maintaining a system in a manner that maximizes profit
or minimizes cost
. Cost functions depending on the reliability
and maintainability
characteristics of the system of interest determine the parameters to minimize. Parameters often considered are the cost of failure, the cost per time unit of "downtime", the cost (per time unit) of corrective maintenance
, the cost per time unit of preventive maintenance
and the cost of repairable
system replacement [Cassady and Pohl]. The foundation of any maintenance model relies on the underlying deterioration process and failure behavior of the component.
Optimal Maintenance strategies are often constructed using stochastic models and focus on finding an optimal inspection time or the optimal acceptable degree of system degradation before maintenance and/or replacement.
There are four main survey papers available accomplished to cover the spectrum of optimal maintenance:
Operations research
Operations research is an interdisciplinary mathematical science that focuses on the effective use of technology by organizations...
concerned with maintaining a system in a manner that maximizes profit
Profit (economics)
In economics, the term profit has two related but distinct meanings. Normal profit represents the total opportunity costs of a venture to an entrepreneur or investor, whilst economic profit In economics, the term profit has two related but distinct meanings. Normal profit represents the total...
or minimizes cost
Cost
In production, research, retail, and accounting, a cost is the value of money that has been used up to produce something, and hence is not available for use anymore. In business, the cost may be one of acquisition, in which case the amount of money expended to acquire it is counted as cost. In this...
. Cost functions depending on the reliability
Reliability theory
Reliability theory describes the probability of a system completing its expected function during an interval of time. It is the basis of reliability engineering, which is an area of study focused on optimizing the reliability, or probability of successful functioning, of systems, such as airplanes,...
and maintainability
Maintainability
In engineering, maintainability is the ease with which a product can be maintained in order to:* isolate defects or their cause* correct defects or their cause* meet new requirements* make future maintenance easier, or* cope with a changed environment...
characteristics of the system of interest determine the parameters to minimize. Parameters often considered are the cost of failure, the cost per time unit of "downtime", the cost (per time unit) of corrective maintenance
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...
, the cost per time unit of preventive maintenance
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...
and the cost of repairable
Repairable
Repairable is a military logistics term for a hardware component of a weapons system that can be designated for repair.Repairable components tend to be more expensive than non-repairable components, known as consumables. This is because for items that are inexpensive to procure, it is often more...
system replacement [Cassady and Pohl]. The foundation of any maintenance model relies on the underlying deterioration process and failure behavior of the component.
Optimal Maintenance strategies are often constructed using stochastic models and focus on finding an optimal inspection time or the optimal acceptable degree of system degradation before maintenance and/or replacement.
There are four main survey papers available accomplished to cover the spectrum of optimal maintenance:
- Optimal maintenance models for systems subject to failure–a review by YS Sherif, ML Smith published in Naval Research Logistics Quarterly, 1981.
- C. Valdez-Flores, R.M. Feldman, “A survey of preventive maintenance models for stochastically deteriorating single-unit systems”, Naval Research Logistics, vol 36, 1989 Aug, pp 419-446.
- J.J. McCall, “Maintenance policies for stochastically failing equipment:a survey”, Management Science, vol 11, 1%5 Mar, pp 493-524.
- W.P. Pierskalla, J.A. Voelker, “A survey of maintenance models: The control and surveillance of deteriorating systems”, Naval Research Logistics Quarterly, vol 23, 1976 Sep, pp 353-388.