iSixSigma

Risk Analysis Tools

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  • #53690

    Beck
    Participant

    We are currently in the process of reviewing our FMEA’s, from the previous year to validate that we have successfully implemented our action items.

    During this process the plant manager asked if there was an easier way to do Risk Analysis, being that FMEAs are so time consuming and in some situations seem like overkill.

    I brought up C&E Matrix and just a simple Risk Assessment tool, and that is when the conversation really got rolling.

    In my mind for smaller projects / processes changes, a simple risk assessment tool should be all that is needed.

    For larger new processes or complex projects you would need to do a full blown FMEA.

    What are your thoughts? I am suppose to read our corporate standards and gleam from it if there is any wiggle room to defend our position.

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    #191117

    Nick
    Participant

    One tool that springs to mind is called Fault Tree Analysis (FTA). This one isn’t quite the same as an FMEA and is useful in situations where you have defects and you want to investigate/assign cause in a methodical way. In other words, an FMEA helps you understand the many different ways that a process can fail while an FTA would focus on a select group of failure modes and help you understand why they occur in your process using data and investigation.

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    #191118

    Beck
    Participant

    Thank you for your quick reply, i see the Root Fault Tree as more of a RCA technique. The question we came up with is there a filter or a set of pre-questions on determining if a full blown FMEA is warrented.

    We are bound by rules established that if we do an FMEA that there is of course considerable amounts of pre-work and maintenance, and we were hoping to see if there was a argument already established showing how a more simpler Risk Assessment would work for certain situations and when it was nessecary to do a full blown FMEA.

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    #191119

    Nick
    Participant

    You are correct – FTA is definitely better suited for analyzing what has gone wrong rather than thinking of ways something could go wrong.

    I don’t know any any rules of thumb that help you decide when an FMEA is necessary. In my experience it has been a judgment call that considers the investment (pre-work, maintenance, …) required to complete an FMEA against the potential benefit. I’ve always gone with my gut feeling or the advice of my MBB. Of course, my experience with FMEAs have always been in the course of 6S project work rather than a matter of day to day work. I’d be interested to see anyone else out there had suggestions on how to determine when you should do an FMEA.

    ASQ gives the following suggestions on when to use an FMEA (I copied these directly from their website) but I doubt this will answer your question either:
    •When a process, product or service is being designed or redesigned, after quality function deployment.
    •When an existing process, product or service is being applied in a new way.
    •Before developing control plans for a new or modified process.
    •When improvement goals are planned for an existing process, product or service.
    •When analyzing failures of an existing process, product or service.
    •Periodically throughout the life of the process, product or service

    Link to ASQ overview of FMEA

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    #191158

    French
    Member

    Particularly when faced with a very broad topic, I’ve focused my FMEA efforts by doing a preliminary screening initially. This works very well with DFMEAs where there is a large system being designed.

    I take each sub-component design and rate it on two scales (rather than the three generally used in an FMEA). I use likelihood and severity most often, but have used complexity and familiarity (with the method) as well. The ranking is limited to low vs. high, so it moves pretty quickly. Items scoring a high/high definitely warrant a full FMEA.

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    #191159

    Frandson
    Member

    Our Risk Management system is based on a 5X5 matrix allowing for Probability ( of the risk happening) and Impact (to our product/process). Probability criteria is rated: 1-can avoid or easily mitigate . . .2-have usually mitigated; 3-may mitigate but workaround required; 4-cannot mitigate; different approach will be needed; and 5- cannot mitigate, no workarounds available. Impact criteria is rated 1-minimal or no impact; 2-minor impact; same approach used; 3-moderate impact; work around available; 4-major impact; workarounds available; and 5-Unacceptable; no alternatives.

    Matrix products 15 trigger Mitigation of the risk. Risks are broadly categorized into Technical issues, Scheduling issues, or Cost issues. A worksheet is kept on each risk as is a ‘score card’ which should (hopefully) show a declining risk product number (or RPN in the FMEA world).

    This is a new program for us so we’re learning, too. FMEA is a little too cumbersome when there are easier tools to get to the ‘low hanging fruit’!

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    #191160

    Beck
    Participant

    Thanks for the Post Rotorwingman,

    It sounds like your facilitiy reach the point of FMEA burn out that we did. Where finally someone just said we need to find a better way.

    Even on the JDI’s we want to employee some sort of risk assessment, especially if there are going to be any moderate purchasing.

    Would it be possible for you to attach the template of your 5×5 matrix, or even a screen shot so I can get a feel for if it would work at my Factory?

    Either way thanks for your response.

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    #191161

    MBBinWI
    Participant

    FTA can be just as onerous as FMEA and for those not familiar with it, can be very frustrating.

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    #191162

    MBBinWI
    Participant

    What specifically is causing difficulty? Without knowing the problem, any solution is just a shot in the dark.

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    #191163

    Frandson
    Member

    Attachment didn’t seem to work; email me and I’ll send along what I have. [email protected]

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