Six Sigma Case Study 1

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 uh 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 so let's get into this case study okay so here we are it's um i mean there's a very simple project title here stage two rework um but actually the the process is a it's a welding process okay so what you're what you're going to see um they're making some assembly and then the assemblies and it's an automatic welder so there's a robot the operators feeding the materials in and the robot does all the work okay and what you're seeing is that the ultimate product uh is a reject ultimately it's rework and they have to then manually correct the problem so currently look rework so here's the define side of things but rework it's causing 50 15 down time at a cost of 800 pound 800 pound per shift yeah so this is a really expensive problem if you just leave it running in the um in the process and they like to get the 15 down to three percent and and then get the the cost per shift down to 160 pound savings from 40 pound a day so there's the sort of very simple uh defying part of the project okay let's do a little bit of measurement so here's the current here's the current problem so you can see they call these stud failures this is a period over two weeks and you can see they're pretty much hitting around about sort of 75 80 a day of these of these failures on this automatic welding process now you're going to see this in all the case studies this is a standard way of getting a process under control you can either get a process under control by using the fmea and you can do this before you go live with the process or what you can do is you can implement the process in a very half-assed way create a problem when the problem gets painful enough then of course what you do is you come back and you use process flow and the process flow diagram is then used this is just describing the process there but the process flow diagram is then used to populate the cause and effect diagram so we're going process flow cause and effect because they've implemented chaos in their process they didn't put these controls in place beforehand so because the the flow diagram now what's it for well we're simply going to visit every box on this diagram and ask ourselves what are the variables in this stage in step one what are the variables in step one what are the variables in step two what are the variables in step three so it's each box you're just going to say okay what are the critical variables that contribute to my welding problem to my rework problem and as i said earlier there's a few photos look of the of the process working here are the um here are the finished products so there they are with the studs welding on these uh bars and there's various stages where the bars are welded on the bars are also bent to shape so there's a it's a fairly complex sort of automated welding and bending process that they've got but the issue is that the welds are simply falling off the studs are falling off and there's the product it's something that goes in concrete floor so you can see the studs here these are what's being welded on and they go in a concrete floor and it's a it's an expansion um it's an expansion joint of some description so once they've gone process flow cause and effect now what are they doing here well of course what they're doing is they're trying to replicate this picture right here so what we've got is a cause and effect diagram all the items on the cause and effect diagram are inputs to the process really important what the cause and effect diagram is about is just identifying all the inputs and it's important all of them are on there whether we think they're a problem or not all of the inputs are on the cause and effect diagram so this diagram is identifying inputs and then what they do is they decide whether the input is controlled or not and the n here against a variable means that it's not controlled okay so that they they don't have any standard they don't have any agreed way of managing that particular variable so you can see there is not a single c now by the way if the variable was under control so we'll take bowl feeder settings what would be next to bowl feeder settings if they were under control a c would be next to them but there isn't it every single variable is an n they've implemented complete chaos into this manufacturing system and consequently the process doesn't work very well so what they're going to do now is they're going to show us how they stepped through the variables that they identified the control now they're not going to control all of these but they're going to control probably i think in the end of the project about 60 of them and they're starting here look with the stacking of the material so one of the problems that the operator noticed is that the material is not in good shape so let's go through what they they've decided to control so now they have a stacking procedure now it's a very simple thing really because what you've got is long bars of metal they're on a pallet and they're all stacked up so it's a it's a really heavy weight that you're storing and one of the things that they keep doing is they store it just sitting on two beams in the warehouse and what happens well the material takes a bend because of the weight of the material that they're they're handling and this very simple standard operating procedure basically says guys we need to control it in the middle as well so they've agreed as standard so now they've agreed to standard written it down now they can audit it and control it okay moving on what else have you got so the the improvement in the handovers so they weren't communicating shift to shift so i think they just put a simple they put a simple log book that's that's quite a common thing but it wasn't in place although it seems like a common sensible thing um that wasn't in place what else did they move on to now they've moved over here look to the condition of the strip oily rusty bent well of course by the very nature of controlling that thing up there they've probably dealt with the the bent strip now this is incoming material though that's that's in these conditions and i believe what they've done is they've now color coded they've color-coded the material so that what because they've got three suppliers and now of course what they can do is they can control the quality of the material from the individual suppliers if they do get a problem they'll see what the color of the material is they'll be able to feed that back to the supplier and then we can we can deal with that but of course what they've done now because is they've given out standards they've come on come up with standard operating procedure for the suppliers and now they're controlling that they know which material belongs to who what else is going on here now we start getting into some of the equipment settings so we're over here now look and by the way just a reminder none of this is complicated none of these things are individually difficult to do but collectively they make a very complex problem but what do you do you break it into inputs you simply break it into a diagram like this and you look at each individual input and each individual solution is simple improving your process capability is really really simple if you have the discipline and the detail to go through every variable individually and fix it come up with a standard way of eliminating the variability your process will behave itself so let's carry on and look at what they are doing on the cause and effect diagram so here we are look now they're looking at the machine as i mentioned earlier so now they're looking at electro change gripper change uh and changing over the product type and you see them now writing standard operating procedures this is for the electrode changeover what else have we got this is a standard operating procedure for the gripper changeover so they're coming up with standard ways of doing simple maintenance setting up of the machine etc replacing of the stud gun is another one okay so again standard operating procedure standard way of doing this identify the variable control the variable and see what happens to the process moving on now they've got a problem with another supplier so the studs come in pre-made and they're supposed to have a flux ball sitting on the end of the stud for the welding process to work some of the flux balls are missing so because that's going to get fed back to the that's going to get fed back to the supplier that needs to be sorted out now of course previously in all the chaos that was going on they didn't know that this was happening they didn't have time to even discover this because there was so much rework to be done all they could do was fix it they couldn't go back and do something proactive so now we've identified the fact that the flux ball is a problem okay now then now we're starting to get these slps all right now we can go back and look at training you see we can do great training now that we have good slps people often say that we're going to train the operators well what are you going to train the operators in if you haven't come up with standard ways of doing work there is nothing to train them in you're just passing on the skill that johnny has got that's a poor way to train anybody now you can train them in standard operating procedures and you can see look i understand that what if they what what have they asked them to do i understand i must work to the standard operating procedures at all times so there's no skill here they're saying there's a standard operating procedure for this variable your role and responsibility is to stick to it and that's it there's nothing else for you to do but to work to the standard operating procedure so they've identified the slps then they can do training then they can identify roles and responsibilities now this is detailed stuff but by the way step by step by step it's all simple this is easy this is really easy if you've got the discipline to do what these guys are doing so back to the training sign-off sheet there's we've got the standard operating procedure now we've got a standard way of making sure that everybody's trained standard way so that they understand what their roles and responsibilities are let's move on okay bowl feeder settings so now we're setting things on the on the machine um one of the things they're saying here look i've told the operators these settings are not to be changed absolutely crucial that's what process control actually means so let's just think about what they're doing so what process control actually means the operators are not allowed to change the settings let's think of it very simply look you have a process choose a pen that works you have a process you have variable one coming into the process and you have variable two which is a setting on the machine so i'm just gonna call this maybe time in this case okay it doesn't matter what it is to make this this point and what you're saying is variable one is coming in with lots of different results so and what's happening of course is out here we're getting lots of variability and maybe we're making defects so because variable one is moving what we'll do is we'll allow somebody to move variable two to fix it well think about the logical thing you're saying i have variability here so i'll fix it with variability here so now the time which would be constant if you just set it and took your hand away time is no longer constant time is being moved up and down now by the operator to try and deal with this well now you have two variables moving what will that result in well it can only result in more variation on the output it's the laws of physics you've got two variables now instead of one this is not process control this is man made that's man-made chaos you're shooting yourself in your in the foot by allowing operators to move variables now what they're doing is to say now we're going to fix this and if this is the problem we'll go and fix this but we won't solve it by moving two variables it just makes it twice as that just makes it twice as worse so let's go back to the case study see what else they got up to so they're fixing the settings in the in the bowl feeder now they found that unfortunately they couldn't fix them to the same settings in theory they are the same bowl feeder but a little bit of common sense here says that if that's not true if they're not the same you know use your common sense don't stick with common settings if they don't work so a bit of common sense there's one has to be at 56 one has to be at 66 this is probably generally the age of the bowl feeder etc but they put them at they put them at standard settings and told the operators you're not to change them moving on then we've got the welder settings here again look what are they saying to the operators you set them and you do not change them we will shoot you if you change them because this is true process control identify a standard fix it and of course with settings there can be no variability because once you've hit that dial and you've said that the the current should be at 500 530 amps it won't move providing you take your hands away and leave it alone then there's an hourly uh check sheet so this is to make sure that the operator is actually following those procedures and something that they've done which is a great little piece of advice they get the operator to write the number so the operator has physically got to write 530 amps or whatever the the setting is it isn't a tick sheet because if you ask him to tick it if you question him about it he will say i was ticking it because it was operating okay now that's not the reason why you do the check you do the check to make sure you're on the standard not to tick that it's working okay so collecting real numbers if you tell somebody that the temperature's got to be 30 the time has got to be 5 seconds and the ampage has got to be 530 get them to write those numbers down and they will always adhere to them in that case they won't want to move off those standards it's a it's a nice psychological way of keeping your operators honest then we've got a little troubleshooting flow diagram this is really good so that what you don't get is again operators taking it onto their own shoulders to fix a problem so here what do they do they just check the standard operating procedures so they're just going through and in each case they're checking that the variable has been set up to the rules because that's their role and responsibility if everything is set to the rules and the machines not working properly then what do you do you call for help you do not try to fix it yourself okay so that's really really important now something else they delved into so they're getting really detailed here they started to look at the three suppliers and say well i wonder if the three suppliers are giving metal that's got the same um compounds in the in the metallic structure so now they're doing some steel test certificates to make sure that that's that that's okay so all the suppliers endearing to what they've been asked for um and once they did all of those things what happened to the process well it can't help itself it has to get better because when you control the inputs you will control the outputs and there you can see the process capability has been improved from approximately 70 defects per day down to about uh what would it be it's difficult to see on that scale but it's around about 17 i would say on average so a dramatic improvement in the process not perfect um and they i think they agree that it's not perfect but they put enough work in the problem no longer hurts them that the pain is no longer so so difficult to deal with the process works so much better and it's so much more reliable and they feel that probably that's as that's as good as they want to get and there's a close-up there's a close-up of where they are i mean those failures look a little bit better than 17 actually it's probably nearer it's probably near at 10 isn't it so fantastic job well done um i can't remember what the the aim was at the beginning but um i think that's that's pretty much i think they said three percent they wanted to get it down to three percent from 15 um and i think that's a lot a lot inside three percent as it turns out um so at the start of the project everything was read everything was out of control at the end of the project look well they haven't fixed everything but look at the work they've done they've done a great job here getting hold of lots of simple variables every one of them was simple but that you have to be disciplined to do this this is what the best companies do this is how to make a process behave itself and improve the process capability and they actually got together two percent look so there's the summary so they managed to get the uh the rework down to two percent so better than they better than they expected and then of course some of the controls they put in place to maintain maintain the gain and as they mentioned here they'll continue working with suppliers and operators uh improving the material and any other slps etc that they that they need to and of course what are they saying once you've got these things fixed what can you do well you can drink tea you can read the newspaper and you can count the cash and that is a great case study okay hope you enjoyed that i'm going to make the point again whether you think that's a simple problem or not whether you think that's a simple process and it's not like your problem it doesn't matter what would your problem look like it'd look like this picture but longer you'd just have more variables but what would we do well they've got about 40 variables they fixed about 30 of them yeah your process might look like 140 variables what's each one going to look like well they're going to look like settings and maintenance routines and setup procedures and things like they're going to look exactly the same just be a longer list of simple things that's the point about this technique it doesn't matter how complicated your process is or how simple your process is inputs control the outputs and what should you do well you should identify the inputs and as much as you reasonably can you should fix them with standard operating procedures rules and then you use iso 9000 what does it do well if you use your iso 9000 correctly you ordered the slps that make money and then iso 9000 doesn't just put a certificate on the wall what does it do it makes money because it's supposed to make money now that is case study one hope you enjoyed it in the next video we'll take a look at exactly this diagram again we'll take a look at another company with a different process doing exactly the same thing in case study two take a look at it [Music]

Channel: Paul Allen

Views: 238

Keywords: lean, six sigma, Six Sigma greenbelt training, Six Sigma Blackbelt Training, Shewhart, Juran, Deming, Taguchi, SPC, MSA, FMEA, DOE, X bar chart, Wheeler, Janam Sandhu, Mrnystrom, Gemba Academy, Full Factorial, Central Composite Design, Ronald Fisher, Hypothesis Test, p value, Histrogram, minitab, Pareto, multi-vari chart, https://youtu.be/QH984PnwRDE, https://youtu.be/f_fjqCpd67Q, https://youtu.be/AGJ1QYI2B4c, https://youtu.be/gsD8V2_eZ0A, https://youtu.be/mM6EyMvvAKk, quality hub india, simplilearn

Id: FVZhlWVN9gA

Length: 26min 6sec (1566 seconds)

Published: Tue Oct 26 2021