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

Table 4

Suggested ranking system for the severity of failure modes [38].

Failure effect	Failure criterion	Ranking	Coefficient
Inconsistent with the safety legislation or the regulations	Hazardous without warning potential safety, health, or environmental issue	10	0.1
	Failure will occur with warning potential safety, health, or environmental issue	9	0.2
Disruption or decline to facility function	The machine runs malfunctioning	8	0.3
	The machine runs properly but moderate disruption to facility function	7	0.4
Disruption or decline to secondary function	Some portion of secondary function is lost	6	0.5
	Moderate disruption to secondary function	5	0.6
Appearance or noise and other functions is poor	Some portion of process is delayed	4	0.7
	Most users (>75%) likely to complain	3	0.8
No discernible effect on safety, environment, or mission	More than half (>50%)of the users likely to complain	2	0.9
	a few users (>25%) likely to complain	1	1.0