Failure Modes and Effects Analysis (FMEA) is a technique used to evaluate potential failure modes within a design, process or service and assess their effects. It helps to identify actions that could eliminate or reduce risks. FMEA was developed by the aerospace industry in the 1960s and is now used in many industries. It involves analyzing possible failures, their causes and effects. Risks are prioritized based on severity, occurrence, and detection for improvement actions. FMEA can be used early in design or for existing processes to anticipate and address problems before they occur.
3. What is FMEA? FMEA is the acronym for Failure Modes and Effects Analysis. It helps in assessing “risk”. Risk is a combination of likelihood and consequences of failure. Goal is to provide an analytical technique usable to assess : Severity Occurance Detectability Deviation from standard Severity : Rating the extent of damage that is likely to occur in case the Deviation occurs. Eg: Process step X if fails causes the entire operation to come to halt. Hence rated 9 or 10 The lesser the damage/inconvenience the lower the rating would be, on a scale of 1-10 Note : Risk = Severity + Occurance Occurance : The likeliness of the stated Deviation in day to day operations is rated on a scale 1-10. The higher the occurance (irrespective of the extent of damage) the higher the rating. Eg: Process step X fails very often(2 times a day), is rated 9 or 10. If occurs once in a month or two, may be 3 or 4. Detectability : The easier it is to detect the better it is for us. The difficult it is to detect, the Longer it could take to be identified/ corrected. This could mean “disaster”. Eg: Process step X failure gets identified through an Andon(alarm). Hence rated 1 or 2.
4. Review Risk Priority Numbers (RPN) : The Risk Priority Number is the mathematical product of the numerical Severity, Occurance, and Detectability ratings: RPN = (Severity) x (Occurance) x (Detectability) The RPN is used to prioritize failure modes that need attention first. The ratings : Though there is a world average to how to rate Severity, Occurance & Detectability, the best way would be to adapt the scoring to the scenario where we are using the tool. The rating scale just need to be able to reflect the three attributes on the 1-10 scale. What is FMEA?
5. What stage can it be used in? FMEA is a tool that can be used at stage of scoping the project : Benefit being able to decide on the chosen modes that needs attention on priority FMEA can be used in Measure stage : To assess the chances of soon 2 be launched Measurement plan’s failing Current Measurement systems lackings FMEA is a standard tool used in Improve stage : To check the strength of the Solution options at hand FMEA can also be used at later stages old Control as the real world scenarios starts affecting : To understand new failure modes coming up To understand the evolving existing failure modes Note : As a standard FMEA is used in Improve stage
7. The Template Note : The Tea preparation example is just attempted to make it simple. Severity of a failure mode usually do not change. Efforts can be made to reduce the occurance/ make it easy to detect the deviation(may be Andon’ize it) Item/ Process Potential Failure Mode S E V Potential Cause(s) O C C Current Control D E T R P N Recommended Action Responsibility/ Target Date Action Results New Sev New Occ New Det New RPN Tea Prep Milk quantity variation 4 Not using measuring cup 5 Keep it handy 7 140 Measure engraved vessel Jeet / 15 Nov 09 4 2 3 24 4 Unable to locate cup 2 Identified place 7 56 Visual control highlighting/ensure proximity Kiran/ 05 Nov 09 4 1 7 28 Milk/Water mix imbalance
8. FMEA : Similar Template (Risk Matrix) Risk Matrix : Can be used to segregate the failure modes on Consequence/Likeliness matrix Likelihood Consequence Negligible Low Moderate High Extreme Not Likely Low Moderate High Expected