Maintenance is the process that preserves or restores a desired state of a system or facility.
Inspection is the activity in which information about state is monitored to allow prediction or early detection of disturbances. Planned maintenance is the activity in which elements of the system are modified or replaced according to a pre-determined schedule, with the aim of avoiding or reducing the frequency of disturbances. Disturbance handling is the activity in which elements of the system are modified or replaced to restore the desired state, following a disturbance. Maintenance is a task that has some important differences from tasks commonly selected for industrial robots. First, maintenance often requires access to environments that are more dynamic and less predictable than is the case for many robotic applications.