Dont you think that it is not correct to go only by the RPN numbers when doing FMEA. Two problems having same RPN numbers would cost the company different amount of money in terms of rectification and lost sales....Moreover it is also possible that for one process the RPN number is low but the cost due to error would be high. In fact combinations of RPN and Quality Costing would be better. I am right now working on combining the RPN number and concept of Quality Costing and your advice can help me in my thesis.

Thanks
Jasmeet

There's no problem with that. You can have a line item with an RPN of 300 which would be too expensive, or it may be a technology issue, or what ever, to address beyond what you already do to control and isolate the problem line item. You do not have to operate only on the top numbers. You DO have to be ready to explain which ones you're operating on and why and why any high numbers are not being acted on. I would expect comments within the FMEA.

Any contemporary comments appreciated!

Maybe I am not understanding the question here. FMEA's are used as a risk management tool and are a systematic method of identifying and preventing product and process problems before they occur. FMEA's are focused on preventing defects, enhancing safety, and increasing customer satisfaction. They are not put in place to identify which potential failures will incur the greatest cost. Just my .02



Murph

Maybe I am not understanding the question here. FMEA's are used as a risk management tool and are a systematic method of identifying and preventing product and process problems before they occur. FMEA's are focused on preventing defects, enhancing safety, and increasing customer satisfaction. They are not put in place to identify which potential failures will incur the greatest cost. Just my .02



MurphAll that is true but, when the cost becomes higher than the benefit of reducing the risk, you draw the line.

All that is true but, when the cost becomes higher than the benefit of reducing the risk, you draw the line.

Al,
I totally agree with that, that is true in any risk management tool. You would still need to identify the risk and have an action plan for it though even if the plan is scrap. If this is that much of a problem I would recommend they look into a little process or product re-engineering and ensure they have optimized their design.

Murph

Al,
I totally agree with that, that is true in any risk management tool. You would still need to identify the risk and have an action plan for it though even if the plan is scrap. If this is that much of a problem I would recommend they look into a little process or product re-engineering and ensure they have optimized their design.

MurphYou're right, but after 6 years, it is moot.

What about when the 'cost of the failure' is lives instead of money?

What about when the 'cost of the failure' is lives instead of money?

My assumption is other risk mangement tools (safe guards, robots, whatever) would be used.

Murph

What about when the 'cost of the failure' is lives instead of money?Those items require a reduction of the risk to zero, in my opinion. There are companies though, that will still weigh the cost of reducing the risk versus the cost of the law suits that may develop. I don't think I have to mention their names since most of the people in these forums are familiar with them.

Risk priority number RPN is calculated as a product of a) Severity b) Occurance and c) Detection. Each values being max 10, RPN is maximum 1000.
One of the commonly made mistake is that many people become complacent by absolute value of RPN. That can be misleading. This is particularly true if RPN # is low but customer has concerns.
What is essential is to take a look at relative magnitudes of RPN to prioritize improvement actions.
It is helpful to generate pareto of top RPN # and compare with customer concerns to decide business case for asking resources for working on improvement projects.

Arvind

There are different views on how to prioritize a "To Do" list from a PFMEA excersize. One (probably most common) is to go strictly by the Risk Priority Number. IMO - this is used by companies that view the PFMEA as a "necessary evil" (satisfy a customer requirement). Another fairly common means is to use S x O and then pareto those results. In my mind, there is no standard "formula" to address what a company should or shouldn't be directing their improvement efforts toward with regard to the ranking indices on the PFMEA. Severities of 9 & 10 definately need to be worked on to have the lowest possible chance to either: a) be produced; or b) be shipped. Normally I look at Severities of 6-8 as "Warranty" issues for my customer and don't wish to ship those either as they tend to get you placed on Contained Shipping ($$$$). The remaining Severities are, in my experience, the "low hanging fruit" which more or less are irritations to the customer and usually need the most "risk vs. cost" attention.

As always - this is JMHO.

What we need to remember is that the FMEA document is not the FMEA--it's only a record of it. FMEA is the process of assessing and mitigating risk. Risk comes in many flavors, and exists in the eye of the beholder (normally the customer). The primary risk in any process in business is fiscal. It's not "If this goes wrong, the product will blow up and someone will be injured," it's "If this blows up and someone is injured, it's gonna cost us." Call me cynical, but the bottom line on the P&L statement is king. So in in answer to your question, yes, cost should always be considered.