S O D参考值

10 9 8 7 6 5 4
> 1 in 2 1 in 3 1 in 8 1 in 20 1 in 80 1 in 400 1 in 2,000 1 in 15,000 1 in 150,000 < 1 in 1,500,000
Low: Relatively few failures 低：相对很少发生的故 Remote: Failure is unlikely 极低：几乎不可能发生 的故障
高
85% - 93%
Very High
很高
93% - 99%
Almost Certain 几乎肯定能
>99%
Absolute Uncertainty 绝对不可能
<1%
Very R%
Remote
微小
5% - 15%
Very Low
很小
15% - 30%
Low
小
30% - 50%
Moderate
中等
50% - 75%
Moderately High 中等偏上
75% - 85%
High
Rank
10
Hazardous with warning 有警告的严重危害
9
Very High
很大
8
High
大
7
Moderate
中等
6
Low
小
5
Very Low
很小
4
Minor
轻微
3
Very Minor None
很轻微 无
2 1
Occurrence （O）故障频数
Occurrence: (Probability of Failure) 故障概率 Very High: Failure is almostinevitable 很高：故障几乎不可避 High: Repeated failures 高：反复发生的故障 Moderate: Occasional failures 中等：偶尔发生的故障 Rank 频数 Failure Likelihood (within 1 year service) 可能的故障率（1年工作时间内）
3 2 1
Probability of Detection (D) 故障检测概率
Detection 检测可能性 Likelihood of Detection 检测故障的可能性 Likelihood of Detection by Design Control 利用现行设计控制方法检测故障模式的可能性 Design control will not or cannot detect potential design cause and subsequent failure mechanism, or there is no design control. 没有设计控制方法能检测故障模式 Very remote chance the design control will detect potential design cause and subsequent mechanism mode. 利用现行设计控制方法检测故障模式的可能性很 微小 Remote chance the design control will detect potential design cause and subsequent failure mechanism. 利用现行设计控制方法检测故障模式的可能性微 小 Very low chance the design control will detect potential design cause and subsequent failure mechanism. 利用现行设计控制方法检测故障模式的可能性很 小 Low chance the design control will detect potential design cause and subsequent failure mechanism. 利用现行设计控制方法检测故障模式的可能性小 Moderate chance the design control will detect potential design cause and subsequent failure mechanism. 利用现行设计控制方法检测故障模式的可能性中 等 Moderately high chance the design control will detect potential design cause and subsequent failure mechanism. 利用现行设计控制方法检测故障模式的可能性中 等偏上 High chance the design control will detect potential design cause and subsequent failure mechanism. 利用现行设计控制方法检测故障模式的可能性高 Very high chance the design control will detect potential design cause and subsequent failure mechanism . 利用现行设计控制方法检测故障模式的可能性很 高 Design control will detect potential design cause and subsequent failure mechanism. 利用现行设计控制方法几乎肯定能检测故障模式
Severity Class (S)
Severity of Effect 严重度影响 Hazardous without warning 无警告的严重危害
严重度等级
严重度等级 Criteria 评分标准 Potential failure mode affects safe system operation and/or involves noncompliance with government safety regulation without warning. 在没有任何预兆的情况下发生的、影响使用安全 或违反有关法律法规的极其严重的故障模式。 Potential failure mode affects safe system operation and/or involves noncompliance with government safety regulation with warning. 在有故障预兆的情况下的、影响使用 安全或违反有关法律法规的极其严重的故障模式 。 System/item inoperable with loss of primary function, but safe. (Such as a locomotive mission failure.) 产品（或系统）不能工作、 丧失基本功能的严重故障模式，顾客非常不满。 System/item inoperable, but at a reduced performance level. Customer dissatisfied. 产品（或系统）能工作、但性能下降的故障模 式，顾客不满。 System/item operable, but comfort/convenience item inoperable. 产品（或系统）能工作、但司职舒适和方便的一 些部件损坏，顾客感觉不便。 System/item operable, but comfort/convenience item compromised. 产品（或系统）能工作、但司职舒适和方便的一 些部件降级工作，顾客感觉有些不便。 Defect noticed by most customers. 加工精细、外观、噪声等方面不符合要求，大部 分顾客能发现有缺陷。 Defect noticed by average customer . 加工精细、外观、噪声等方面不符合要求，有一 半顾客发现有缺陷。 Defect noticed by discriminating customer . 加工精细、外观、噪声等方面不符合要求，但很 少有顾客发现缺陷。 No effect. 无影响