/prə-vä-kə-tiv mānt-nən(t)s/
[common ironic mutation of 'preventive maintenance']
n. 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; this results in the machine's remaining in an *un*usable state for an indeterminate amount of time.
See also scratch monkey.