The Six-Sigma process is a very powerful process, as we saw in the improvements that we see in quality as we go from three Sigma to Six-Sigma, to obtain this power, we need to have a formalized way of making improvements in our process. The Six-Sigma methodology uses a process which is called the DMAIC. The DMAIC is an acronym for a process that has five steps. These five steps are define, measure, analyze, improve, and control. So, the D-M-A-I-C which are the first letters of each of this steps of this process create the name DMAIC. Now, each of these steps has a particular role. Let's start out with the first step of the process, which is Define. As the name suggests, in the Define phase, we want to know what is the problem that we are concerned with? So, this is where we come up with the identification of the problem and scoping of the problem. So, we want to know what is this problem? Who does it affect? In a sense, who are our customers? If we know who our customers are, we want to have what's called the voice of the customers. So, you want to know from our customers how it affects them when they have a problem. Because Six-Sigma is a very rigorous methodology, we want to make sure that we are very careful about deciding how we measure what this problem is. So, we want to know what is it that we are going to be measuring? Why do we think there is a problem? Now, it could be that we have failures occurring of our product when they go out to our customers, and maybe the measure is the number of failures per thousand parts shipped. Or it could be a DPMO measure. It could be that we are concerned about the weight of material that we are packaging in our packaged product. So, what needs to be measured is that weight of the product that is actually in the package. So, we need to figure out what is it that we are going to measure? How are we going to measure, and how do we know that a problem exists? Beyond that, to define what this problem is, we may want to create a project charter. Now, a project charter basically identifies what the problem is, why is it important, who's going to be working on this project, who is sponsoring this project, so on and so forth. Then, we need to identify what the project team is. Now, in the project team, again, we will talk a little bit more in detail about some of the elements of a Six-Sigma project team. But usually, you want to know who's involved, why are they involved, and what is their role in this particular project. Now, a tool that is commonly used to do this define step is called the SIPOC tool. Now, the SIPOC tool, basically, the SIPOC is another acronym. The SIPOC comes from the words suppliers, inputs, process, outputs, and customers. So, the first letters of this create the acronym SIPOC and that's what we are looking at. It's a relatively simple tool to understand the scope of what we are planning to work on. So, let's look at an example to see how one would use this SIPOC tool to come up with a definition for the problem. Let's take the example of making a grilled cheese sandwich, and I purposely chose something relatively simple. For those of you who don't know what a grilled cheese sandwich, if you're not from the US and have not seen a grilled cheese sandwich, it is essentially two pieces of bread that have butter, and a slice of cheese is put in between, and it is then grilled on a pan. So, if I wanted to create a SIPOC for the making of a grilled cheese sandwich, the first thing I'd like to do is I'd like to understand what is the process. Once I identify what the processes of making a grilled cheese sandwich, I can move out on in both directions and fill out the rest of the terms in the SIPOC. So, as I just explained, the process of making a grilled cheese sandwich is the following: Now, when we define a process in the SIPOC methodology, this is remember, very early stage where we're just trying to get some handle on what it is that we're trying to do. So, we tend to not get too detailed about how to go about making the details of the process. We want a fairly high level explanation of what's being done. So, here's a high level explanation that I put together for making a grilled sandwich. So, what do you do? You get a plate. On the plate, you keep your slices of bread and you apply butter to the bread. You stack the bread and cheese together to make a sandwich. You go and heat the pan on the stove. You take your sandwich and you place it on the heated pan. You flip it so that both pieces of bread are heated. Then, when it's done, you take it off and you place the finished sandwich on the plate again. So, that's my process. With this particular process, what are the things that I needed to make this sandwich. So, I need to know what my inputs are. So, what are the things that I needed. Well. I needed a plate, that's where I started out. I needed bread, I needed butter, I needed cheese. I need a pan. I need a spatula so that I can flip things on the pan, and then I needed a stove, so I can heat the pan. Now, where do I get these inputs? That's my source. So, my source, I might get the plate from a cupboard. I might get my bread, butter, and cheese from the grocery store. My pan, my spatula, maybe also in the cupboard. My stove is in the kitchen. So, those are my sources to get the inputs that I need to make the process. What's my output? My output in this case, is a hopefully delicious sandwich. But in the process, I also generates some waste. What are the wastes that I generate. Well, I had a wrapper that went around the cheese, and so that rapper has to be disposed. So, one of the outputs is waste, which is the cheese wrapper. Who are my customers? My customers might be my family. How specific I want to get about family is up to me. I might decide that I need to get more specific, instead of saying family. I might say my spouse and my children, because each of them might have some different ideas of what a grilled cheese sandwich should be like, and so I may need to consult both of them to figure out what is the requirement for this grilled cheese sandwich. Oftentimes, you will see in a SIPOC at the end of the customers, might be requirements that were obtained from the customers about what the output of this process are to be. Should it be a heavily buttered sandwich or a lightly buttered sandwich. There's might be specific requirements that the customers might tell us, so that we know whether our sandwich actually meets our customers requirements. So, that's the SIPOC tool. It's really that simple. It tends to be a very simple tool to just organize our thoughts about what it is that we want to do in this particular Six-Sigma project. Having defined our project, we then go on to the Measure phase of Six-Sigma methodology. Now, Six-Sigma methodology is very rigorous in that we want to make sure that things are quantifiable, that things are measurable, and that we do go about getting extensive data to backup whatever it is that we say. Now, we will never know if something has been improved if we don't know where we started. So, the first thing we want to do is establish a baseline. So what we do is we say, "What are our key performance indicators? What is it that we are going to measure to know that we are performing according to some standard?" So we may specify what are our key performance indicators or KPIs. Then, maybe we will need to know how are we going to measure once we've identified what we are going to measure we need to know, how we are going to measure those things, all right? So when I talk about producing a grilled cheese sandwich, how do I measure whether it's a good grilled cheese sandwich? I could think of a few different things. I could think about the temperature of the grilled cheese sandwich when I serve it to my customer. I could look at something like the amount of grease or butter on the sandwich when that is given to the customer, and then I might have something that is a little less obviously quantifiable, a little more subjective, the taste of the sandwich when I give it to my customer. To figure out the taste, I might create a 10-point scale and ask my customer on a scale of 1-10, "How do you rate the sandwich?", and then get a numerical value out of that. But I need a way to measure. This quantifiable performance measure is called the Y in Six Sigma methodology or in the DMAIC process. The reason why it's called a Y because we are trying to write an equation in some sense where our Y is the output and it's going to be equal to some function of a bunch of inputs that are going into this particular Y. So, that's our measure phase. Once we are done with the measure phase, once we've identified how we are going to evaluate the output of our process, we get into the analyze phase. The analyze phase, essentially, is to find what might be the root causes of the problem that we've identified. Now, it's possible that we may many root causes. It's possible, for example, if you identify that our grilled cheese sandwich is awful, there could be many reasons why that happens. The cook is terrible, the ingredients are terrible, maybe the equipment is terrible. So, it's possible that we have several possibilities. In this case, personnel or the manpower, the inputs, the ingredients or materials, the equipment which is a stove or it could even be possible that the ambient temperature in the kitchen somehow affects the quality of the sandwich that's produced. So there could be many such root causes. A common technique that's used that we will not discuss in detail here is a fishbone diagram or an Ishikawa diagram. In this, all the possible root causes are identified, and then those root causes are investigated further by using the Five Why process that we talked about when we talked about lean management. Now, once we've looked at multiple root causes or all potential root causes, we try and figure out which of those root causes are actually important. So, we have to prioritize because we could end up with 20-30 different root causes or reasons why something could go wrong and not all of them are equally important. So, what we like to do is we like to prioritize; we like to figure out what is the importance of each one of those. Then, one way to do that, for example, is to think of the inputs that are going in and each of those root causes is now an input and we call it the X's. So, remember we have an equation which says Y is equal to the function of the inputs so it is the function of the X's. So, we figure out which of those X's are important and we try to build a statistical model to measure the effect of the X or the input on the output. Now, the models that we may use in this case could be fairly complicated statistical models, they could be very intricate regression models, or they might be analysis of variance or NOR models, but we need to do it in a way that we can actually come up with something that's measurable where we can show that indeed the input has an effect on the output. So, notice that already in this DMAIC process, we are starting to talk about statistical techniques. This is one of the strengths of the Six Sigma methodology because it forces you to come up with quantifiable results that you can defend at least statistically that what you're claiming is indeed correct. Now, once we've analyzed the problem, once we've figured out what the root causes are and the contribution of each of the root causes are to the output that we are observing, the next step obviously is to try and improve the process. So, how do we go about doing that, right? So, obviously we want to brainstorm solutions and there are lots of different ways that people can create brainstorming sessions. When you come up with a brainstorming session, you often come up with lots of possible solutions. Now, the idea is not to sort of analyze to depth any particular process, but to start acting and trying to improve the process right away. So, you start out with the easiest solution, what's called working on the low hanging fruit to see if you can get improvements quickly. You then test the solutions. You may use something like the PDCA methodology we talked about in lean management. This is the plan, do, check, act methodology where you say, "If I make this change, does it actually improve the process?" And if it does then I look for the next change and so on. So, you want to test your solutions to make sure that what you're saying is going to improve, actually does improve. If it does, then you need an implementation plan. This implementation plan has to take whatever new idea that you've come up with to improve the solution and try and deploy it practically so that once you leave, it will continue to keep the process at a higher level or it will keep the process at that improved level because of this new improvement that you've created. After you've done that, so the Six Sigma methodology basically has now improved the process. But how do you know that this improvement will remain? So for that, we have what's called the control phase. This is how do you sustain the improvement that you obtained by going through this rigorous process of defining, measuring, analyzing and then improving the process. So, you have to figure out who is responsible to do the things that are required to make that improvement a lasting improvement. How do we measure that we've actually improved? Because we know that we have variability in our processes, we know our processes tend to drift. So, how do we know over time that whatever change we made has actually improved things? So, we may use statistical control charts. There are a number of charts P-charts, C-charts, et cetera, X-bar charts, R-charts that one could use to make sure that our process remains in control after the improvement phase. So, once again, you see the importance of using statistical techniques to make sure that process improvements do occur. So, that's the DMAIC process in short.
