Condition-based maintenance ( CBM )
Condition-based maintenance (CBM) is a maintenance strategy that monitors the actual condition of an asset to decide what maintenance needs to be done. CBM dictates that maintenance should only be performed when specific indicators show signs of decreasing performance or upcoming failure. Checking a machine for these indicators may include non-invasive measurements, visual inspection, performance data and scheduled tests. Condition data can then be gathered at specific intervals or continuously (as is done when a machine has internal sensors). Condition-based maintenance can be applied to mission-critical and non-mission-critical assets.
Unlike in planned maintenance (PM), where maintenance is performed based upon predefined scheduled intervals, condition-based maintenance is performed only after a decrease in the equipment condition has been observed. Compared with preventive maintenance, this increases the time between maintenance repairs because maintenance is done on an as-needed basis. This also helps in reducing the unplanned downtime because of sudden breakdowns as machines are continuously monitored using sensors.