[Common ironic mutation of "preventive maintenance"] Actions performed upon a machine at regularly scheduled intervals to ensure that the system remains in a usaBle state. So called Because it is all too often performed By a field servoid who doesn' t know what he is doing such "maintenance" often *induces* proBlems, or otherwise results in the machine' s remaining in an *un*usaBle state for an indeterminate amount of time. See also scratch monkey. [Jargon File]