Which type of maintenance includes both planned and unplanned service activities?

The correct choice involves unscheduled maintenance, which encompasses both planned and unplanned service activities. This type of maintenance is characterized by tasks that must be performed on an ad-hoc basis in response to the immediate needs that arise from equipment failures or performance issues.

Unscheduled maintenance typically occurs when there is a breakdown or unexpected malfunction of equipment, requiring immediate attention to restore functionality. In addition, it can also involve routine checks that, while not specifically scheduled, are necessary when certain conditions arise. This approach allows for flexibility in addressing issues that were not anticipated.

In contrast, preventative maintenance focuses specifically on routine activities planned ahead of time to mitigate potential failures, targeting the overall longevity and efficiency of equipment. Periodic maintenance, similar to preventative, follows a set schedule based on time intervals or usage metrics but doesn’t encompass unexpected service requirements. Reactive maintenance, while also closely related to responding to failures, does not differentiate between planned and unplanned service activities to the same extent that unscheduled maintenance does, as it often implies a response only after a failure has occurred without any forward planning.

Thus, unscheduled maintenance effectively captures the essence of both necessary immediate repairs and routine service activities that arise unexpectedly, making it the most appropriate choice.