Fuzzy comprehensive evaluation for the reliability of gearbox shell production line

The following reliability indexes are calculated based on the observed one year and a half maintenance records for two gearbox shell production lines after 10 years of running: F(t), R(t), MTBF, MTTR, K, A and C. By contrasting the dynamic indexes of these 2 lines, we find out that the reliability of flexible line is lower than that of the rigid line. Furthermore, we build a fuzzy comprehensive model based on the static indexes above by using fuzzy math and AHP method. This model validates the conclusion of the difference in the reliability of the two production lines. Finally, we analyze the underlying reason of such reliability difference of these 2 lines.