TThhee GGrreeeenn BBeelltt SSiixx SSiiggmmaa TToooollkkiitt x ⎛ 2⎞ ORDER 1 ∫ ⎜ 1 ⎡x −μ⎤ ⎟ F(x) = exp − ⎢ ⎥ 2π σ ⎜ 2 ⎣ σ ⎦ ⎟ ⎝ ⎠ BUILD −∞ TEST OK? SHIP D M A I E C SSiiggmmaa QQuuaalliittyy MMaannaaggeemmeenntt © Sigma Quality Management, 2007 No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, for any purpose, without the written permission of Sigma Quality Management, Raleigh, NC. Table of Contents The Green Belt Toolkit - Table of Contents Section Title Page Introduction iv 1 Improvement Methods 1-1 2 Measuring Performance 2-1 (Graphs and Charts) 3 Pictures of the Process 3-1 (Flowcharts and Layout Diagrams) 4 Tools for Improvement 4-1 (Pareto, Histogram, Scatter Diagram) 5 Cause and Effect 5-1 (The Fishbone Diagram, FMEAs) 6 Selecting, Planning & Making Improvements 6-1 (Selection, Testing, Implementation) 7 Maintaining the Improvement 7-1 (Process Control, Control Charts) 8 Working on a Team 8-1 (Team Skills, Decision Making, Meetings) 9 Examples 9-1 10 Exercises 10-1 11 Forms 11-1 Index I-1 Appendix A Answers to Exercises A-1 Appendix B Accelerating Change B-1 Appendix C Bibliography C-1 Introduction INTRODUCTION TO THE GREEN BELT TOOLKIT Welcome to the world of Six Sigma and the cadre of “Belts!” We’ll assume you are reading this manual because you’ve been selected or “volunteered” to become a Green Belt for your company. We’re not going to try and tell you what a Green Belt is – hopefully, your company has a well-defined roles and accountability description (if not, start yelling right now!). Let’s focus on the basic premise of this manual: In today’s business world, the only sustainable strategy for growth and success is the continual improvement of products and services and their associated “production1 processes.” In a nutshell, that’s what Six Sigma is really all about (if your company is using Six Sigma just for cost-cutting, you can be sure the program will be short-lived). In Frederick Taylor’s day, improvement was the sole province of management. Workers and their suggestions didn’t really count. Today, we have to engage everybody in improvement. All minds are important. Everybody from the company CEO to entry-level employees must be active in moving the organization forward (yeah, that includes YOU!). One of our friends, Bill Conway, used to tell the “nuclear” people at Florida Power & Light, “As a Vice-President, it would take me at least two or three years to foul up this plant, one of you maintenance folks could do it in a heartbeat, with one wrong turn of a wrench!” Now, we’ve seen many companies that are good at changing, but change does not necessarily equal improvement (i.e. most re-organizations don’t count!). To improve our odds in this game, we need to understand the variables that affect performance, implement changes that address these variables and check the effects of our changes - in short, we need to practice the scientific method when attempting improvement. But this doesn’t mean that we have to learn very complicated methods. Fortunately, many, many “opportunities” faced by organizations can be solved with a few basic improvement tools and methods. That’s where you, the Green Belt, will play an important role. Almost 20 years ago, Japanese counselors working with Florida Power & Light told us that over 90% of a company’s problems can be solved with just 7 basic tools (Graphs, Check-sheets, Pareto Analysis, Cause & Effect, Histogram, Control Charts and Scatter Diagrams). Well, we believed them (sort of!), but it took us a while to understand how right they were. So, practically, how do we go about improving our products, services & “production” processes? There are a few basic elements: First, we need a method to guide us. Section 1 presents several methods of process improvement, with a focus on the DMAIEC approach. Although we’re mindful of Dr. Deming’s warning that “All models are wrong, some are useful,” this is a general-purpose approach, one that has gained fairly wide acceptance in the Six Sigma community. The Black Belts in your company are likely using a similar process improvement approach – y’all can then talk the same language. 1The term “production” fits whether you produce a product or a service. We’re definitely not limiting this discussion to manufacturing. In fact, we like to challenge our service-business clients with the concept of their “production processes!” iv Introduction Measurement plays a critical role in process-focused improvement - it helps us listen to the “Voice of the Process” and compare that to the “Voice of the Customer.” We will need some tools to help us understand how our products and services are performing and where there are “problems.2” Section 2 will cover this topic. Section 3 describes some ways of picturing the process. Sitting down and creating a flowchart of how some work process occurs can often generate many suggestions for improvement. There are also some specialized process pictures used by different industries that may help you develop a “picture” that best suits your process. Sections 4 and 5 are the core of this manual. If you walk away from this manual understanding and practicing only two tools, please let them be Pareto and Cause & Effect. Dr. Kaoru Ishikawa, one of our heroes, said that over 80% of problems could be solved with just these two tools. We’d agree. In Section 6, we focus on selecting and planning and making changes to the process that will hopefully improve performance. There are some minor issues, such as costs and benefits that we may want to consider as we try to “sell” and implement our solutions. We don’t want to be getting rid of mosquitoes with elephant guns! You’ll find that it takes hard work to change a process. After you’ve improved the process, you don’t want to see your hard work “slip-slidin’ away!” Section 7 talks about how to ensure your changes become a “permanent” part of the way you do business. While we don’t advocate teams just because they are popular, sometimes you’ll need to bring a group of people together to work on a problem. Section 8 provides you with some ways of helping these groups work together more effectively. Over the years, we’ve been fortunate to have been part of many improvement efforts. Section 9 will share some of these with you; in Section 10 you’ll have the chance to “practice” with some practical exercises. We hope you find these methods useful. John J. O’Neill, Jr. President, Sigma Quality Management P.S. We’ve read too many of these books that were written in a third-person, boring style. We prefer the first-person-plural, corny, but friendly style. We hope that you agree, but if you don’t, at least we had fun! 2A “problem” for us is merely a gap between where something is now and where we’d like it to be - one of our products could be doing great now, but if we expect it to do even better, then there is a “gap,” and hence a “problem.” v 1. Improvement Methods 1. IMPROVEMENT METHODS This section’s purpose is to provide you with methods to improve your products and services. Now, just why do we need an improvement method? Well, if you’ve ever baked a cake, changed a car’s engine oil, rewired a traction motor on a diesel locomotive, or performed open-heart surgery, you know that having a method to do the work is very helpful. The method helps guarantee the success of the project. In essence, the method is our plan that helps make sure we’ve covered all the bases and done so in the right sequence. The same thing is true with improvement. If we get our improvement “recipe” out of sequence or skip steps, then we may not be successful in our goal of improved performance. Most of us are already good at jumping from a problem to solution. That works if you’re changing a light bulb. But if you’re not sure what’s causing the problem, you might want to do a bit of analysis first. Another reason for adopting a “standard” improvement method lies in its communication power. Often, an organization’s improvement efforts will require bringing people together from different departments to address an issue. Manufacturing, engineering and purchasing may work together, nursing, pharmacy and the laboratory may address an issue, sales, billing and shipping may need to work on a problem affecting them all. A common improvement method can help accelerate the project. Right from the start, everybody knows how we’re going to work through this effort. Now this appears to be a somewhat intangible benefit, but we’ve experienced it so often, that we’ve come to value its importance. Example: A rehabilitation unit in a hospital was having trouble making progress on improving their scheduling system. We gave them a simple “design process” to follow; the supervisor later said that once the team saw that this was a “fill-in-the-blanks” framework, they got excited and worked through the process in less than one month. They had struggled for six months prior to receiving the “design process.” There’s another communication issue to address. Often, a manager will charter a team of people to work on a specific improvement project. Periodically, that manager will want to review the progress of the project. When it comes time to implement the recommendations of the project team, he or she will want to know the basis for the recommendations. The common improvement method not only facilitates work within and across departments, but also helps communication up-and-down the chain- of-command. We’ve seen maintenance technicians stand up in front of company vice-presidents and be able to clearly tell their improvement “story” because they all spoke the same improvement “language.” Before we jump into the actual methods, though, there’s a danger we must point out. One of our heroes, the late Dr. W. Edwards Deming, had a saying,”All theories are wrong, some are useful.” 1-1 1. Improvement Methods An improvement method is a “theory.” We prefer to think of improvement methods as frameworks, and not as “cookbooks.” They help us frame the way we think about solving a performance problem that we have with our products or services. We’ve seen too many “quality police” out there proclaiming that if the team doesn’t do this step or use this tool here, then the whole effort will be “wrong.” For a long time at Florida Power & Light, if the “Current Situation” step of our improvement method did not contain a Pareto diagram, the team “must” have done something wrong. Teams would make up Pareto diagrams and put them in their improvement stories, just to avoid this criticism. This kind of lock-step thinking is totally against what we’re trying to achieve. Beware of the Quality Bureaucrats!!! 1-2 1. Improvement Methods 1.1 PROBLEM SOLVING Let’s spend a few minutes addressing a common activity, that of problem-solving. Problem-solving is both a precursor to improvement and also contains some of the necessary elements of improvement. Captain James T. Kirk of the starship Enterprise was great at problem-solving. So are Superman, Wonder Woman, Batman, Miss Marple, Sherlock Holmes, and most CEOs and managers. The fact that the “superheroes” generally take 30 minutes to an hour to solve problems and their corporate counterparts take slightly more time is merely a constraint of television programming; of no consequence here. Now, problem solving is a necessary part of life. We solve so many problems each day, we’re not even conscious of the process we follow. But let’s examine the basic steps of problem-solving: Step Example It’s Monday morning, you’ve got a staff meeting in 30 minutes and you’ve just put the meeting notes in the copier. The Problem Nothing happens when you push the “Start” button. Since you feel resourceful, you start looking around to see what the problem might be. The copier is on; you’ve Your Analysis pushed the right buttons for number of copies, collation, stapling, etc. So what’s the problem? You finally notice the “OUT-OF-PAPER” light blinking on the control panel. Great! You’ve found the problem’s cause. Your S olution You look around for the usual box of copy paper sitting next to the machine, but it’s not there. So you run down to the supply room, grab a few reams of paper, run back and refill the copier. The R esult You now push the “Start” button, the copier does its thing, and you’re ready for the staff meeting with 10 minutes to spare. Success - you’ve solved the problem! Now this is a pretty simple act of Problem-Solving, but it illustrates several points: The first point is simple - there is a process that we follow. This is important because a good problem-solving process can be applied to many, many problems. In fact, we can improve our ability to solve problems by getting better at applying this process. One responsibility of managers is to help their people grow in their ability to solve problems. We help our children learn how to solve problems, why not our employees and staff? 1-3 1. Improvement Methods A manager that we called the “Lone Ranger” was very, very good at solving problems. He would hold back while everybody else mucked about, and would not contribute until the rest of us were desperate for help. Then, he would ride over the hill; solve the problem and sit back waiting for the credit. Unfortunately, he never thought it important to teach his people how to solve problems. Second, the problem-solving process because it is the precursor to our improvement method. We broke problem-solving down into four steps: Identify the Problem - We first have to recognize that there is a problem (sometimes, we live with problems so long that they are not recognized as such!). In our example, it was simple. There was a gap between what we wanted to happen and what did happen. There was also “pain” - if we didn’t get the copies made, we wouldn’t be ready for the meeting, presumably with some consequences (wasted time, confusion, etc.). Analyze the Problem - After recognizing the problem, we have to analyze the cause of the problem. If we don’t know “why,” then we don’t really know what to do about it. In our everyday lives, this step sometimes does not occur, or is not done well. We often tend to “jump to solution” without going through an analysis of “why.” Can you recall examples where people in your organization jumped right from the problem to the solution? How many times has this resulted in the problem not being solved? Develop a Solution - Of course, once we know why the problem occurred, we need to identify and implement a solution that addresses the cause. This path, too, is fraught with peril. We’ve got to make sure that the solution does, in fact, address the cause of the problem and will lead to the desired result. If your solution was to call someone from Supply, the paper may have been delivered, but perhaps not in time for you to make the copies for the meeting. Check the Results - Finally, we need a “check” step - did we solve the problem? In our example, the feedback was immediate; in many cases, feedback may occur days, weeks, or months later. Our third point will help us transition to our improvement method. In the copier example, you solved the problem, but we’ll claim that all you did was implement an immediate remedy. This particular instance of the copier being out of paper was resolved. Nothing you did, though, will prevent the reoccurrence of the problem. What do you think the odds are of finding the copier out of paper next Monday? Although there are many similarities between problem-solving and true improvement, this is one of the key differences we’ll need to address. Finally, we don’t want to fool you into thinking that these few pages tell you all there is to know about problem-solving. For example, the process we described here follows the “break-the-problem-down” or analytic approach. We started with some symptoms and diagnosed the cause of these symptoms. We changed one part of the “system” that produces copies. For this problem the analytic approach was appropriate. There is also a synthetic approach to problem-solving. This is often referred to as getting “outside the box,” or “outside the nine dots,” depending on which “game” introduced you to the concept. The history of invention is full of this kind of problem-solving: The Swiss got better and better at making mechanical watches, until the quartz watch blew the old watches out of the water, FEDEX™ institutes over-night shipping and takes a big piece of the US Mail’s business away, the personal computer replaces the mainframe (and the central information management department!), etc., etc. 1-4 1. Improvement Methods 1.2 GENERAL IMPROVEMENT PRINCIPLES Let’s start with some basic principles that should apply to a process improvement method: First, what are our requirements for an improvement method? Well, the first two are somewhat conflicting: Easy to Use and General. Some methods we’ve seen that are easy to use (usually because they are more “cookbook-ish”) are only good for a certain class of improvement efforts. For example, one method called FOCUS-PDCA is primarily useful for improving the processes that “produce” services. On the other hand, we’ve developed improvement methods for organizations whose main focus has been on the root cause of equipment failures. This takes a different kind of thinking and, hence, a different improvement method. Second, the improvement method must be both customer and process-focused. The customer-focus must be there, since our improvements should aim towards achieving “faster/better/cheaper” for our products and services. The process-focus must be there because the actions that we take are directed at the production processes that “make” our products and services. The third requirement is that the improvement method must incorporate the business equivalent of the scientific method - the Plan-Do-Check-Act Cycle, or PDCA. A form of this PDCA cycle was first articulated by Walter Shewhart, a statistician/engineer working at Bell Laboratory during the 1920’s and one of Dr. Deming’s mentors. In fact, the PDCA cycle is often called the Deming-Shewhart cycle, since Deming popularized it: Deming-Shewhart Cycle The PDCA cycle is the “engine” of process-focused improvement. PLAN-DO-CHECK-ACT is both the basis for an improvement method and a philosophy of management. PDCA asks that we Plan our products, services and their production processes, that we Do the work of production, sales and delivery to customers, that we Check the performance of the product and service at ACT PLAN meeting customer needs and requirements and that, based on “gaps” discovered, we Act to revise the product, service and production process (thus revising the Plan and bringing us full-circle). CHECK DO Now we can use the PDCA cycle to design new products and services. But, to improve an existing product or service, we’ll make use of the “CAP-DO” cycle: CAP-DO recognizes that you are already producing products and services. You are already “DO-ing” the work. The CAP-DO cycle will ask you to first “CHECK” the performance of the product or service and, based on “gaps” in its Quality, Cost, Service (Delivery) or Safety characteristics, you will study the process and its variables. You will then “ACT” to change the important variables, thus revising the “PLAN.” “DO-ing” the work brings you back to the “CHECK” phase, where you will see how well your process changes worked. Sound simple? It really is, but it takes discipline to practice. 1-5