Design Failure Mode and Effect Analysis (FMEA) and Fault Tree Analysis (FTA)
Design Failure Mode and Effect Analysis (FMEA) is a method of predicting the failure modes of major functional parts and assessing the impact of those modes on a system (product). Fuji Xerox applies design FMEA from an early stage of the "Virtual" phase by utilizing simulation and calculation results obtained by Computer Aided Engineering (CAE). We can also assess the impact of each failure mode more precisely than before by linking this design FMEA with the Engineering-Parts list (E-P list) that relates the basis of design to the features of parts.
We use our standardized original FMEA format (Fig. 1) to comprehensively evaluate the frequency of occurrence, impact, frequency of detection, and risk of each failure mode, so as to devise the most optimal preventive measures and improve product quality.
FTA logically describes the process that results in the occurrence of certain failure, starting from that failure (phenomenon). It shows the concatenation and combination of events that caused the failure in the form of a logic diagram (Fig. 2), and is a method of identifying the fundamental cause and mechanism of occurrence.
We use FTA to analyze past trouble in the market and trouble that occurred during the development of predecessor products, and then store the results as recurrence prevention lists in a database. By utilizing the information in this database from an early stage of the "Virtual" phase, we are now able to implement measures against the fundamental causes, which can only be addressed at the beginning of design.