[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 doingsuch "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]