Types of Maintenance: Main Strategies and Alternatives
Equipment, machines, systems, and installations have been evolving and changing over time, becoming increasingly sophisticated, requiring continuous improvement in maintenance planning and more rigorous work on the part of the maintenance manager.
Role of Plant Maintenance in production Management – MBA TUTS
Despite developments in equipment and facilities, maintenance needs remain the same. For this reason, and understanding maintenance as a set of technical actions to regulate the normal operation of these same pieces of equipment, we can divide it into three major groups:
(1) Corrective Maintenance, also known as reactive maintenance or breakdown maintenance;
(2) Preventive Maintenance, which is regular maintenance performed according to defined schedules, regardless of the condition of the equipment;
(3) Predictive Maintenance, or condition-based maintenance, which is based on the constant monitoring of the operating equipment and predicting the occurrence of failures.
In this article, we’ll explore the advantages and disadvantages of each of these types of maintenance and compare each of them with the alternatives.
What is Corrective Maintenance?
When a piece of equipment malfunctions, it must be repaired (or replaced!). This is the assumption of corrective maintenance, also called reactive maintenance. In other words, it is the technical activity performed after a malfunction has occurred and it is intended to restore the asset to a condition in which it can function normally, either by repairing it or replacing it.
As this approach is characterised by maintenance actions after a failure has occurred, it is ideal for low priority equipment, that is, assets whose absence won’t stop the company’s operations from continuing to function normally.
The same applies to equipment of lower value, as the work required to maintain or constantly monitor it can prove more expensive than repairing or replacing it when it breaks down. A simple example would be a lamp, which can be used until it melts and should then be replaced.
Given that very little planning is needed for this approach, its implementation cost is very low compared to the alternatives.
The problem is relying on corrective maintenance for medium or high priority assets. Since no preventive actions are taken in a Corrective Maintenance strategy, the lifetime of the equipment will end up being shorter than with one of the alternative strategies.
If applied to high-priority or high-value equipment (it shouldn’t!), it may lead to unexpected stoppages and possible huge repair costs.
We should not, however, mistake corrective maintenance with emergency maintenance, which occurs at different stages of a breakdown. While corrective maintenance is carried out at a time when certain physical damage or disturbance in the normal operation of the equipment is notorious (i.e. a functional failure), emergency maintenance occurs after total failure of the equipment, which requires urgent maintenance (and has generally higher costs).