Effects of Preventive Maintenance on the reliability of production lines

In determining failure characteristics in typical manufacturing production lines, workcells and components can have different failure patterns and distributions at the same time. The preventive maintenance (PM) of a production line is normally conducted on parts of machines or components in the system. Often, this type of PM does not restore the entire production line back to "as-good-as-new" condition - the entire production line is generally 'imperfectly' repaired. A production line can be subject to multiple such PM actions over its operational life span. In determining an optimal PM strategy, an accurate estimation of the effects of these PM actions on the reliability of production lines is essential. This paper addresses this issue at a component level using the split system approach (SSA). The repaired components are assumed to be connected logically with the rest of a system in series. Most existing models consider the entire system and are based on the premise that the effect of PM is dependent on the characteristics of the failures of a system. This research revealed that the effect of PM depends on the characteristics of the failures of repaired components rather than the entire system.