FMEA best practice - Design FMEA links to Process FMEA

welcome to complexity made simple my name is paul allen and before we get on to today's video just a reminder of how you can support the channel please subscribe please leave comments on all the videos because that really does help but if you want to support the channel further there is a donation page please go to buy me a coffee and leave a donation which is always fantastically helpful keeps the channel keeps the channel moving and allows me to make all of this fresh material but if you want a textbook that contains all the good stuff from the videos please click on the link and buy drink tea and read the paper from lulu.com all of these things really help the channel thank you to all the people that continue to buy this textbook it really is fantastically helpful now let's get on to today's video welcome to complexity made simple my name is paul allen and the subject of today's newsletter we are going to take a look at failure mode and effects analysis we're going to take a look at fmea and in particular we're going to take a look at what fmea is supposed to achieve as a generality not necessarily the detail of the fmea that's for another video but we're going to take a look at the two styles of fmea there's a design fmea and there is a process fmea we're going to take a look at these two techniques and how what they're supposed to do is to give you high fidelity control at the production level and make sure that you please the customer and that's what these two things are designed to do so we're going to talk through the principles i'm going to use a little silly little example but it'll make a point as to how design fmea and process fmea are really supposed to work together so the example we're going to take a look at we're going to look at the idea of uh designing this remote control for this is the wrong control for my tv so so we're going to start with a designer from here now if you take a look at the form here this is the fmea form that we'd normally use this is my fmea form at a process level because that's normally the fmeas that i'm teaching people so i don't have one that's specifically for design but in this first column here the column wouldn't say process step it would talk about the component the part that's going into this particular uh tv remote control so the form would be slightly different but we would be starting with that first column the part now you'll notice that the second column over says what is critical to quality and this is really important what the design fmea is going to do it's going to capture the designer's intent why did he design the product the way he did why did he come up with tolerances the way he has that's what this thing's gonna do not just come up with tolerances not just come up with raw materials it's gonna come up with the reason why he did it so if we take our remote control and we say okay what's one of the things that's critical to quality about the remote control and we'll say that it's strength we need this thing to be strong why do we need to be strong because some fat guy who's more interested in watching the football than looking at the remote control might come along and sit on it on the sofa so we have to have a certain strength to this okay so that's the critical to quality so what's critical to quality about the about the plastic case so that's what we'd be looking at we go it's the plastic case okay what's critical to quality about that case strength and of course we could put a value to this let's say we wanted to resist i don't know 50 kilograms not probably enough for a big fat guy but 50 kilos maybe okay so that's the that's the strength that we want now as you work across the fme air course you're going to decide what risk this is and how much money you want to spend on this is it really important that we do this so and then of course at the end you're going to say okay given that i do want to sort this out what control am i going to put in place so let's say we decide through the fmea this is important we've got to do this this is critical to quality it's important to the customer because of course if you sit on it and destroy the remote control the remote controls are not usable it's not going to be it's not going to have a happy customer so okay so he decides now controls let's use this he decides now what are his controls that he's going to put in place well the controls he puts in place now this is his design intent he so i've got it i've got to deliver this here's my design intent so he decides to go for glass filled uh i'm going to say glass filled nylon okay so he decides that the raw material he's going to use is glass-filled nylon and he decides that the wall thickness has got to be one millimeter and because the thickness there's a certain level of safety on this uh in terms of calculating its strength etc maybe he doesn't have to put a particularly tight tolerance on it so he says it's one millimeter plus or minus 0.1 now that's his design intent that's that's what the fmea was designed to capture it was designed to capture the thoughts of the designer not just all the extraneous nonsense that could happen like i wonder if the customer might drop this down the toilet i don't watch the tv on the toilet very often but i wonder if they might drop it down the sink while they're doing the washing up and watching tv at the same time that type of kind of strange event is what we typically capture in an fmea but that isn't what the fmea is for it's to capture your design intent the customer needs this how do we react well we react with those two controls there now the process fmea has to deliver these two because the process fmea has got the same requirement it's got a process step so so for the for the process fmea it won't say what's the component it'll say what's the process step you can see it on this form here that's the way i've designed it look process step then next to it it says what's critical to quality about this process step well if this process step was the injection molding stage of the production process what would be critical to quality well that we use glass filled nylon and that the wall thickness is held to a particular size and a particular tolerance okay now what we're going to do of course is we're going to work across the process fmea and again now we're going to decide whether this is important or not and how do we decide if it's important well we can look right across the design fmea if we want to you're not just going to figure this out off the top of your head here these are manufacturing engineers they don't know what the designer had in mind when he put that tolerance there but if they look at the design fmea they'll they'll know exactly why that tolerance is there so they'll know how important this is so again we're going to get to the point where controls are needed okay and let's say it's this this is what we're talking about the glass filled nylon's really relatively easy to control but this we're trying to control the plus or minus 0.1 of a millimeter now what some people put here they will put we'll measure it we'll gauge it now quite honestly that's not a control that's a filtering system that's basically saying we haven't got a clue how to do this so because we don't know what we're doing we're just going to grade all the crap out and throw it in the bin well that's a terrible control that's not a process control it's just a gatekeeper to the rubbish that you're producing now now process control we're not going to measure it we're going to figure out what settings exist on the molding machine that guarantee this we're gonna we're gonna guarantee that this happens now we identify two controls so we'll say temperature of the tool needs to be i'm gonna i'm just gonna make something up 150 degrees and the tool must be cleaned weekly and if i do those two things i'll hit this now when someone says well this is expensive oh and and this oh we're gonna have to buy a new control system to be able to achieve that do we really want to spend the money well you can decide because you can follow this this thing follows right the way through for the point where the customer has got a particular requirement now that is the way fmeas are supposed to work when i'm looking at the bottom and by the way this is a proper control plan because what's he doing it controls inputs that's what a control plan does it doesn't measure outputs measuring outputs is just a gatekeeper it says we don't know what we're doing so we'll measure the crap out of it that's rubbish control the inputs we're going to do these two now if you think that these two are expensive or difficult to do or whatever you can now ask the question why are we doing this well you can go because we're trying to maintain this specification hey why are we trying to maintain this specification in because the customer wants this why does the customer want this because they're going to sit on it while they're watching the football is that important to the customer or not now you can decide whether you want to do this or not how many times have you had to write a concession where you can't hit a tolerance and you don't know why the tolerance exists it happens all the while it used to happen all the world to me why did it happen all the while because we didn't have the design intent we've got the design intent of the way we design the product we've got the design intent of why we designed the tolerance and therefore we've got the design intent of the way we designed the process and why these two things exist and now of course if we accept them and i just put those in place and i control the inputs guess what i never have to measure the output i'm never going to measure this i know these two control the bloody thing that's control that is a control plan if you ever put check it here check it measure it gauge it inspect it that's not a control plan it's an inspection plan what does fmea do if you really do it properly it guarantees zero defects and it guarantees happy happy customers and if you get those two things you will make pots and pots of money that is what your fmea is for okay there's fmea now just before we finish the video just a couple of things if you'd like to know more about my thoughts about six sigma and fmea because there's some detail about how to do an fmea it's covered in this book drink tea and read the paper please buy the book if you're interested in finding out how to do this properly also if if you want to make any comments you want to make an argument or discuss this any further please leave some comments in the box below that would be really helpful and of course the final thing is take the six sigma challenge if you invite me in and i can't make your processes work better if i can't make a technical problem go away inside your company when we use six sigma if i can't fix it don't pay me take the six sigma challenge but otherwise leave some comments below if you'd like some other videos to be made tell me what you want in the comments and i'll make whatever whatever video makes sense so hopefully i'll hear from you soon [Music]

Channel: Paul Allen

Views: 361

Keywords: Lean, Six Sigma, FMEA, Capability analysis, Cpk, Ppk, Cp, Pp, SPC, DOE, MSA, Shewhart, Juran, Deming, x bar, PPAP, APQP

Id: pn9XXbltkRA

Length: 15min 0sec (900 seconds)

Published: Tue Oct 12 2021