Wrench time is the amount of productive time in a day. It is the time spent actually doing PM, corrective maintenance or even fixing breakdowns. It does not include getting parts, manuals, driving to a broken down unit, jockeying units in the yard, etc. Traditionally wrench time was defined as time spent by the worker with tools working on the machine. It includes direct troubleshooting. By convention we now include LOTO, Confined space entry set-up as part of wrench time. Your productive maintenance and repair activity comes from your wrench time. Obviously if you have enough people for your workload and projects then wrench time is of lesser importance. But if you struggle to meet all your demands then the wrench time becomes urgently important.