【Quality Version】One Question per Day 2016-6-26 (Short Answer Question)

Answer: “S” for severity, a value that corresponds to the most severe consequences of the given failure mode. “The occurrence frequency of O” refers to the likelihood that a specific cause/mechanism will lead to the occurrence of a failure mode. “D” is the detection measure, corresponding to the level of the detection control listed in the existing control detection bar. “RPN” refers to the Risk Priority Number, a value that helps in determining the priority of risks; it is equal to Severity (S) x Occurrence Frequency (O) x Detection Difficulty (D)

SOD is Severity (S) / Occurrence (O) / Detectability (D) / RPN Risk Priority Number

The formula for calculating the Risk Priority Number RPN is: RPN = S × O × D. Where S is the severity factor, representing the seriousness of the consequences (1-5); O is the occurrence frequency factor, indicating the probability of it happening (1-4); and D is the detection difficulty factor, representing the probability of it being detected early (1-4).

SOD is Severity (S) / Occurrence (O) / Detectability (D) / RPN Risk Priority Number

“S” severity, a value that corresponds to the most severe consequences of the given failure mode. “The occurrence frequency of O” refers to the likelihood that a specific cause/mechanism will lead to the occurrence of a failure mode. “D” detection degree, corresponding to the level of the detection control listed in the existing control detection bar. “RPN” stands for Risk Priority Number, and the calculation formula is: RPN=S×O×D.

“S” severity, a value that corresponds to the most severe consequences of the given failure mode. “The occurrence frequency of O” refers to the likelihood that a specific cause/mechanism will lead to the occurrence of a failure mode. “D” is the detection measure, corresponding to the level of the detection control listed in the existing control detection bar. “RPN” refers to the Risk Priority Number, a value that helps in prioritizing risks; it is equal to Severity (S) x Occurrence Frequency (O) x Detection Probability (D)

“S” severity, a value that corresponds to the most severe consequences of the given failure mode. “The occurrence frequency of O” refers to the likelihood that a specific cause/mechanism will lead to the occurrence of a failure mode. “D” is the detection measure, corresponding to the level of the detection control listed in the existing control detection bar. “RPN” refers to the Risk Priority Number, a value that helps in prioritizing risks; it is equal to Severity (S) x Occurrence Frequency (O) x Detection Probability (D).

SOD is Severity (S) / Occurrence (O) / Detectability (D) / RPN Risk Priority Number

The formula for calculating the Risk Priority Number RPN is: RPN = S × O × D. Here, S is the severity factor, representing the seriousness of the consequences (1-5); O is the occurrence frequency factor, indicating the probability of it happening (1-4); and D is the detectability factor, representing the probability of it being detected early (1-4). Severity S is used to assess the impact of potential failure modes on the equipment, with 10 representing the most severe impact and 1 indicating no impact at all； The occurrence rate O represents how often a specific cause or mechanism of failure occurs, as well as the probability of its occurrence; a value of 10 indicates that it will almost certainly occur, while a value of 1 indicates that it hardly ever occurs. 　　The detection degree D is a measure of the probability of failure modes in equipment failure detection; a value of 10 indicates that detection is not possible, while a value of 1 indicates that it can be detected effectively. The worst-case value for RPN is 1000, and the best-case value is 1. Based on the RPN value, projects are identified, and responsible solutions along with completion dates are recommended; the ultimate goal of these recommendations is to reduce one or more risk levels. For some serious issues, even though the RPN value is low, rescue solutions are still considered; for example, a possible failure mode with a risk level of 9 or 10 ； A possible failure mode/causation event occurs with a very high severity level.

S: Severity coefficient O: Occurrence coefficient D: Detectability D: RPN: Product Risk Priority Number