Table 1 Common industrial maintenance strategies
Strategy | Intent | Benefits | Weaknesses | Suitability |
|---|---|---|---|---|
Reactive | Only undertake maintenance when a complete equipment failure occurs | No upfront planning or scheduling | Unpredictable equipment availability, shorter equipment lifetime, increased energy costs, and potentially lower production yield due to partial malfunctions | Suitable for non-essential equipment, or in situations where the cost of maintaining equipment is greater than the cost of failure |
Corrective | Identify and address individual/minor faults when they occur to avoid a complete equipment failure | Manages risk of complete failure, provides visibility of equipment health, and can increase lifetime of equipment through timely maintenance activities | Investment in diagnostic technologies, as well as the labour cost associated with monitoring and managing faults | Suitable for broad classes of equipment maintenance, but may not be suitable for mission critical equipment, where a complete failure must be mitigated at all costs |
Preventative | Perform regular maintenance to avoid either partial or complete equipment failures. Preventative maintenance can be undertaken at time intervals (e.g. change component X every 4 weeks regardless of its state), or when a particular condition has been met (e.g. heating element begins to take X minutes to reach its target temperature) | Promotes confidence in machine availability by mitigating equipment failure using pre-determined maintenance intervals/conditions | Prematurely replacing components and carrying out maintenance activities may come at the expense of high maintenance costs, or at least costs that are sub-optimal | Suitable for scenarios where every attempt must be made to ensure that mission critical equipment is available and operating correctly at all times, but this is typically done at the expense of resource efficiency and cost |
Predictive | Predict an issue before it occurs and be capable of estimating the remaining useful life (RUL) of the equipment and/or its internal components | Optimises resources and reduces costs by predicting the lifetime of components to avoid premature replacement and circumvent redundant maintenance activities | Given prediction is probabilistic rather than deterministic, there is potential for false positives that could lead to unnecessary maintenance actions | Suitable for scenarios where the operation, cost and output derived from equipment must be optimised, but occurrences of machine availability can be tolerated |