Unplanned maintenance is also known as: reactive maintenance, corrective maintenance, breakdown maintenance, or run-to-failure maintenance.

Unplanned maintenance occurs in any asset maintenance plan and unfortunately is unavoidable.  A common example of this type of maintenance (and the inconvenience that it can cause) is having your car break down on the side of the road, and having to wait for a mechanic to come to repair it.

The trigger for this type of maintenance is a breakdown trigger.

Problems associated with unplanned maintenance

Because this maintenance type is both unplanned and unscheduled this method of performing maintenance activities is highly inefficient. Time needs to be spent investigating and determining the problem as well as determining a maintenance plan to get the equipment fixed quickly. Time is also likely to be spent waiting for parts, supplies or other personnel to complete the maintenance task.

This type of maintenance can also be very expensive. Additional costs include time spent waiting, the premium costs that may be spent on fast part orders and shipping, and the possible overtime payments that may be required for additional, or specialised personnel needed to complete the task. In addition, because it is likely that the operation of other parts of the facility will be negatively impacted by the breakdown of the machine in need of repair, the costs of lost production need to be also factored into the cost of this type of maintenance.

If no maintenance planning is undertaken then this style of maintenance becomes the default maintenance style. This is because the planned and predictive maintenance styles described later need an investment in planning before they can be successfully utilised.

While it is intended that this type of maintenance should be avoided in the planned maintenance strategies such as predictive and preventative maintenance , it is inevitable that, at some stage, a machine will break down and unplanned maintenance of this type will be required. This incurs all of the additional costs associated with this type of maintenance.