Industrial Cases Reports

Transcription

Hi there. My name is Ron Pereira and I'd like to officially welcome you to this first overview module of the Gemba Academy 7 QC tools course. By the end of this module you'll know what quality control is, you'll understand the benefits of quality control, and you'll know what the 7 QC tools are. You'll also begin to see how the 7 QC tools can help your organization improve no matter what type of work you do. To be sure, you don't have to manufacture widgets to practice quality control as we'll learn throughout the rest of this course. Okay. Well let's get things started by offering a definition of quality control. And to do so we're going to hear from one of the giants of quality control, Dr. Kaoru Ishikawa, the person credited with defining what we call the 7 QC Tools today. Well when asked to define what quality control was, Dr. Ishikawa said, "...that it consists of developing, designing, producing, marketing, and servicing products and services with optimum cost-effectiveness and usefulness which customers will purchase with satisfaction." Now from this definition it's clear that Dr. Ishikawa felt quality control was far more than visually inspecting parts at the end of the assembly line. In fact, Dr. Ishikawa often spoke of Total Quality Control or TQC which saw quality control spread to all facets of the organization including front office tasks. So that's what it is. Now let's now turn our focus to the benefits of quality control. First, when quality control becomes a way of life the number of defective products will decrease and as such, over time customer satisfaction will increase leading to enhanced trust and loyalty. And from an internal perspective, consistent quality control lowers costs for the company since people aren't wasting time reworking parts and waiting for good parts to be produced and, as such, profits increase year over year. So you see, done correctly, quality control reaches all aspects of our business which results in happy and loyal customers. Now then, the tools most often used for problem solving by organizations well versed in quality control are called the Seven QC Tools. Now for the rest of this module, we'll take some time to introduce them and then throughout the rest of this course we're going to be taking a deep dive into each tool explaining how they can be applied in both manufacturing and transactional environments. But before we get into the tools, I'd like to provide a little background on how these concepts developed. And as it turns out, the Japanese began applying quality control during the 1930's and 1940's after Dr. Walter Shewhart and Dr. W Edwards Deming introduced the concepts. Dr. Kaoru Ishikawa, the then head of the Japanese Union of Scientists and Engineers decided to expand the use of these tools in the 1960's with the introduction of what we now call the Seven Quality Control Tools. Dr. Ishikawa chose these 7 tools as a way to make the use of quality control accessible to anyone, no matter their experience with statistics. Well the first of the 7 QC tools is the graph. Now most of us have seen or used graphs at one time or another. With graphs, data are expressed to easily compare quantities or quantity changes. They're also used for arranging data, sharing information with others, and making judgments. Now in our next module, we'll not only explore several different types of graphs, but we'll also explain how to choose the correct graph to use. The second QC tool is the Check Sheet which are tables used to arrange data by type. Now we also use these simple, but powerful tools, for checking if jobs are completed without problems and for preventing mistakes from happening at all. The third QC tool is the Pareto Chart. Now Pareto Charts classifies problems and defects by type in the order of quantities and shows the cumulative total. Now Pareto Charts are often used for checking a problem or defect to be highlighted for solution. In other words, Pareto Charts often help us identify where the problem is as we learned about in the Gemba Academy Practical Problem Solving course. Again as a reminder, Pareto charts get their name from Wilfredo Pareto, the Italian economist who was the first to identify the so called 80-20 rule. Well the fourth tool invented by the aforementioned Dr. Ishikawa is the Cause & Effect diagram, sometimes called the fishbone. Now the cause and effect diagram systematically arranges the results of effects and the factors that influence them. With this information, we're able to classify causes and their potential influence on the problem at hand. The fifth QC tool is called the Scatter Diagram which is a graph used to examine the correlation between variables by plotting corresponding data. In other words, Scatter Diagrams help us examine the relationships between two variables and whether or not they're associated, or correlated, with one another. Now, we'll get into different variations of the Scatter Diagram including regression later in the course, but I do want to mention an extremely important aspect of studying correlation. Namely that correlation does not automatically mean there is causation. Now an example of this is how in some cases it can be statistically shown that as the number of liquor stores in a town increases so do the number of churches built. So one could conclude that if a town hoped to have more churches all they need to do is build more liquor stores, right? Well of course this is complete nonsense since the two, liquor stores and churches, aren't correlated at all. Now a better explanation for this situation is that as a town grows in population , there'll be some who like to visit liquor stores and some who like to attend church. Next, we come to the Histogram which is a graphical display of numerical data in the form of upright bars. With histograms, we're able to learn many things including how much variation, or spread, a data set contains. Now when we add in customer specification limits, which we'll learn more about later in the course, we're able to calculate something called Cp and Cpk which basically tells us how well our process meets customer requirements. And last but certainly not least, we come to the Control Chart which is a tool used for judging the situation of quality values against control limits in order to check the stability of a process. Now Control charts also help us to understand whether we're dealing with common cause or special cause variation which is an extremely important information to know as we work to control quality across all levels of the organization. Now we first learned about common cause and special cause variation in our Practical Problem Solving course, but as a quick refresher common cause variation could be likened to the normal everyday traffic we experience on our commute each day to work. And special cause variation could be likened to when there's an accident and traffic comes to a complete stand still. Alright. Those are the 7 QC tools. As promised throughout the rest of this course, we're going to take a deep dive into each one separately explaining how the tool can be applied in both manufacturing and transactional environments. Additionally, throughout the rest of this cours,e we're going to learn how to create each of these tools using Microsoft Excel and Sigma XL statistical software. Alright, well this wraps up this overview module. In our next lesson, we're going to dive right into things as we gain a deeper understanding of the many different kinds of graphs available to us. So we'll speak to you soon.