Understanding the basic concept of manufacturing equipment Reactive Maintenance

Reactive Maintenance is done at a point when there is a repair or actual breakdown. It occurs when repair action is taken on a problem only when the problem results in machine’s failure. Unplanned downtime, in it’s simplest definition, breakdown maintenance simply means fixing when it fails. It is a strategy which tells us that when a machine fails, then it is time for maintenance to fix it. Limitations of breakdowns maintenance is that it is cause unplanned downtime and production delays which results in revenue losses and extending the maintenance of work overtime to fix the equipment. Repairing the equipment after it fails usually creates the possibility of secondary damage which increase the maintenance cost. Allowing failures to occur can be applied to the asset if the consequences of failure and the cost of repair is minimal and acceptable to both the user and maintenance.
The common mind set of maintenance personnel is that “if isn’t broke, don’t fix it. And when it breaks, will fix it”. When this is the sole type of maintenance practice, then the consequences involves the high percentage of unplanned activities, high replacement and parts inventories and high pressure to keep the equipment running. A pure reactive maintenance strategy ignores opportunities to influence equipment reliability and survivability. A justifiable instance includes if it does not produce critical delays, it does not sacrifice people’s safety and it does not significantly increase costs.

In Reactive Maintenance, we must consider the following:

1.“Run to fail” is valid if a failure is evident and does not affect safety or environment, or if it is hidden but does not affect safety or environment, then default decision is “not scheduled maintenance”. Run to fail maintenance is valid if suitable scheduled tasks cannot be found for hidden function. And a cost effective preventive task cannot be found for failures which have operational or non-operation consequences.

2.“Redundancy or standby”. Duplicating the system or component failures are allowed or being tolerated through redundant or duplicated functions.

3.“Alternative means”. The presence of redundancy or alternative means of production is a feature of the operating context which must be considered in detail when defining the functions of these assets in its present operating context. Often times termed as standby- unit, even with the same equipment type, standby-units have different degree of maintenance requirements as the duty unit and most failures for standby unit are hidden. To set an example, in civil aviation, a high number of items classified in the redundancy level allowing failure to happen. When the aircraft is in the air, back-ups are use just in case failure is experience when the plane is in motion. Since safety is the priority, failures are then allowed to happen.

In assessing a Reactive Maintenance task, the assessor should be guided accordingly; if the monitoring, scheduled maintenance or inspection required for safety or environmental compliance; if the breakdown will be more costly than the task or preventing the failure itself; if the equipment in the critical path in manufacturing or considered a bottleneck equipment or process; if the back-up equipment is not available; if the breakdown adversely affects delivery or customer service or provide any delays; and lastly, if the breakdown further damage the equipment or provide secondary damages. Then Reactive Maintenance is justified.