Six Sigma DMAIC Process - Improve Phase - Failure Mode Effect Analysis (FMEA)
FMEA identifies all the probable failure modes for the product or process. It prioritizes the failure modes for focused attention by using a scoring model based on Severity (S), Occurrence (O) and Detect ability (D).
RPN = S*O*D
Based on the above suitable action plans can be created to contain the risk. It is used as a living document and could be a good foundation for building robustness.
Definition of Terms:
Failure Mode – The way in which a specific process input fails
Effect – The impact the failure has on the Critical Quality Parameter
Cause – The source of variation that caused the process to fail
Current controls – Systemized devices in place to prevent or detect the failure
Severity – Importance of an effect on critical quality parameter (1-Not severe; 10 – very severe)
Occurrence – Frequency with which a cause occurs (1-Not likely; 10-Very likely)
Detection – Ability of current control to detect the cause before creating a failure mode (1-likely to detect; 10-not likely to detect)
RPN is an acronym for Risk Priority Number. It is calculated by multiplying the Severity, Occurrence and Detectability.