Accumulated duration of the individual maintenance times used by all maintenance personnel for a given type of maintenance action or over a given time interval. NOTE 1 Maintenance man-hours are expressed in units of hours. NOTE 2 As several people can work at the same time, man-hours are not directly related to other parameters like MTTR or MDT (see definitions in Annex C.5).
Source: API STD 689, Collection and Exchange of Reliability and Maintenance Data for Equipment, First Edition, July 2007. GlobalStandards