Reliability Importance Measures considering Performance and Costs of Mechanical Hydraulic System for Hydraulic Excavators

Table 1

Suggested ranking system for the occurrence of failure modes [37].

Rank ()	Comment	Failure frequency	Coefficient
10	Extremely high	≥0.2	0.1
9	Very high	≥0.1	0.2
8	Repeated failures	≥0.05	0.3
7	High	≥0.03	0.4
6	Moderately high	≥0.02	0.5
5	Moderate	≥0.01	0.6
4	Relatively low	≥0.005	0.7
3	Low	≥0.003	0.8
2	Remote	≥0.0005	0.9
1	Nearly impossible	≥0.0001	1.0