Maintenance Terminology Can Cause a lot of Confusion and Discussions
The vocabulary used to qualify the interventions varies from one company to another and in big companies, even from one plant to another. Moreover, every experienced maintenance professional has an opinion regarding the meaning of terms and definitions. And although each country has a recognized standard organization, which has issued a dedicated maintenance vocabulary, the reality is that the maintenance world is very far from having a universal agreement concerning the meaning of basic maintenance terms and confusions of terms still occur.
Many professionals believed that the adoption of CMMS a couple of years ago would motivate maintenance teams to establish clarity. But this didn’t happen! Two different plants would use the same CMMS, but two different vocabulary lists to designate the performed interventions. The same intervention would therefore be described differently from one site to another. And on the same site, two technicians would qualify/interpret the same intervention sometimes in different ways.
5 good reasons why the use of a standard maintenance vocabulary is essential:
- To express clear and precise ideas.
- To initiate a constructive dialogue between the production and the teams of technicians in the company or group.
- To compare different factories data within the same group.
- To share analyzes, data and important files with other maintenance technicians working at other companies.
- To obtain coherent KPIs approved and understood by all.
The team of Mobility Work suggests you some important but forgotten definitions of basic equipment maintenance terms:
Maintenance: Maintenance is the set of actions performed to maintain or restore property in a specified state or to ensure a specified service. The maintenance department is in charge of these actions.
Equipment Availability: Availability means that the time available to a production team to operate a certain piece of equipment (machine’s opening time) is devoted to the machine’s main function: to produce.
For example, a packaging line with 100 hours per week available to the production team should, ideally, package products for 100 hours. Obviously, this is not realistic. A 100% availability of equipment is purely theoretical, but allows a good understanding of the concept.
A 95% availability means, from a maintenance point of view, that 5% of the time was consumed by maintenance, and 95% was devoted to production. The 5% correspond to the maintenance technician's interventions on the equipment: lubrication, control, repair of a belt, replacement of a detection cell, etc.
Measuring availability is therefore a good indicator of the performance of a maintenance department.
The measurement of equipment availability consists of:
- The machine’s opening time. For example: equipment that is scheduled from 5am on Monday morning to 5am on Sunday morning, including preparation and cleaning time, will thus have an opening time of 144 hours / week.
- The time spent by the maintenance department on a piece of equipment which equals the total duration of the different interventions that affected the machine. In Mobility Work, this will be the total duration of the tasks associated with a piece of equipment.
We can then define the availability of piece equipment, normally expressed as a percentage.
Preventive Maintenance (PM) is planned maintenance, aiming at improving equipment life and avoiding unplanned maintenance interventions.
Total Productive Maintenance (TPM) encompasses proactive, preventive and autonomous maintenance actions. It is based on the 5 Japanese S: seiri – sort; seiton – set in order; seisso – shine; seiketsu - standardize; shitsuke – sustain and 8 supporting activities:
- Autonomous maintenance
- Planned maintenance
- Quality integration
- Focused improvement
- Early equipment management
- Training and education
- Safety, health, environment
- TPM in Administration
Corrective Maintenance is performed as fast as possible after a failure has occurred or has been identified to restore an asset to an operational condition respecting the scheduled times for in-service operations.
Asset maintenance management is a continuous improvement strategy for extending the lifecycle of assets (systems, facilities, equipment and processes) by ensuring their availability, safety and reliability. A solid asset maintenance management should decrease the frequency of breakdowns and minimize downtime.
Autonomous maintenance (level 1 maintenance) is a crucial component of TPM. Autonomous maintenance is carried out by the machine operators and not by dedicated maintenance technicians. Machine operators are expected to understand the functions and the components of the machines, detect any possible issues and perform corrective maintenance tasks.
Predictive maintenance: Compared to the time-based preventive maintenance, predictive maintenance analyzes the current condition of a piece of equipment and predicts a potential failure before it occurs. Thus, predictive maintenance enables maintenance technicians to foresee the exact moment of a breakdown and intervene only when necessary.
Spare parts management is the main component of an effective asset management program. Spare parts management ensures the proper planning and control of spare parts inventory in order to guarantee operational reliability and plant capacity. The right spare parts should be always available when needed and the right quantity of each spare part should be precisely defined in order to avoid excessive costs.