Maintenance framework
As briefly mentioned earlier, not all maintenance operations are at the same level of complexity, urgency or planning. They can therefore be classified according to several criteria.
Type of intervention
Interventions can be either corrective or preventive. In the first case, the intervention cannot be planned, as it is carried out following the failure or degradation of the machine’s function. In the second case, the intervention will have been planned and the equipment will have been prepared, as the aim of these interventions is to reduce the probability of machine failure or degradation.
Corrective action may be temporary (troubleshooting), to bring the machine back into temporary operation as quickly as possible. In this case, they are palliative interventions. They can also be definitive, restoring the machine directly to its original state, or to an improved state that eliminates the fault. These are then known as curative interventions. In both cases, these maintenance operations are often carried out under severe time constraints.
- Systematic maintenance, carried out according to a schedule based on a predetermined number of usage units (time, products, rotation, weight, etc.);
- Conditional maintenance, which is triggered when a predetermined, significant threshold of machine degradation is crossed;
- Predictive maintenance, triggered by analysis of the evolution of the machine’s state of deterioration.
Defining maintenance levels.
Each increase in level generally entails an increase in the complexity of the task, its duration, the planning of the intervention, the skills required and the documentation required. It is logical to assume that this increase in level will also be followed by an increase in the risk associated with the intervention, due to the increase in energy sources to be isolated, the increase in logistical resources, the increase in machine dismantling and the increase in the size of dismantled parts.
However, machine design can limit or accentuate the increase in risk. To counter these risks, the machine can be padlocked during dismantling.
Furthermore, the first two levels are not exclusively reserved for maintenance personnel. In fact, production operators are also called upon to carry out this work, in order to enrich their task and involve them in machine maintenance.
