FAULT-BASED UNIT REPLACEMENT

PROBLEM TO BE SOLVED: To provide a method and system which determines the end of durable period for a replacement unit which may be associated with a multifunction device and has a useful durable life based upon a number of operations.SOLUTION: A counter associated with a multifunction device continues counting operations for a unit. Once the number of performed operations of a replacement unit reaches a given percentage of the expected durable period of the unit, analysis is performed on an occurrence history of fault codes. Once the number of fault codes attributable to any given replacement unit reaches or exceeds a predetermined level, such as a percentage of the occurrence history, a notification indicating a need to replace the replacement unit is generated.