We discussed cause and effect diagrams in the yellow belt. It's an important topic, so we'll discuss it again, and add some more variations. The cause and effect diagram was created by Kaoru Ishikawa in the 1960s, it's a formal brainstorming tool for identifying possible root causes. The purpose of a cause and effect diagram is to gather information from as many people as possible, and to explore all possible causes of a problem. It allows you to identify, explore and display a problem and all possible causes in a structured way. Strangely, this tool has three commonly used names, Ishikawa called it a cause and effect diagram, others have it called an Ishikawa diagram in his honor. And because of it's appearance, many people call it the Fishbone diagram, these are all names for the same tool. There are lots of ways to brainstorm ideas, the fishbone or Ishikawa diagram is somewhat structured approach to brainstorming It is specifically aimed at identifying potential causes. This is the basic layout of a fishbone or ishikawa cause and effect diagram, you see it looks like the skeleton of a fish, and our analysis is intended to identify major factors, those are the big bones that contribute to the problem. And then, further write these down into more elementary causal factors, those are the little bones that caused these factors to create or prevent problems. There are many different suggested categories for fish bone diagrams, but you don't need to be constrained to follow any of them. The major reason for the labels on the big bones is to get participants to think of different types of classes. This scheme [COUGH] is probably the first one that was widely used and you can make up your own categories, whatever fits you an apartment of your applications is best. You do not need to confine yourself to a certain number of categories, the number of bonds is not critical, but it is usually forward to six. Let's consider a few other examples, oftentimes, customer service problems are caused by the institution's policies. Legitimate and necessary policies May cause problems for a variety of reasons. The policy intended for one purpose may have unintended consequences at another area. A policy may have become obsolete but remains in place, a policy may be applied incorrectly because it's poorly understood or ambiguously defined. A policy may be causing problems because no one has bothered to identify legal approaches to living with the policy and still accomplishing what needs to be done. Procedures are a frequent source of perceived waste and customer service problems. When a customer is looking for service, they're not likely to enjoy being told they must follow some lengthy procedure that from their point of view has little or nothing to do with the service that they're looking for. Long lists of required signatures, multiple forms requiring redundant information, and inexplicable waiting periods cause people to feel like the procedures, rather than their needs are what's driving the process. Service enterprises involve lots of people who interact directly with customers as such, people represent our greatest opportunity to delight customers and our greatest opportunity to disappoint them. People must have the knowledge, skills and authority to provide the service that our customers are looking for. Every time one of our employees has to say to a customer I don't know how to do that or I tried but it didn't work or I'm not allowed to do that. We've created a situation, where our people disappointed our customers. Finally, we have potential problems with our physical plant or facilities, this can include lack of facilities or lack of access to these facilities or old and outdated facilities that do not meet customer expectations. Naming schemes seem to fit different situations better than others, it's really not important which scheme you use or whether you create your own. The important thing is to consider lots of different types of causes to use a fish bone diagram, first draw the fish bone structure With the problem at the head. If you have a carefully constructed problem statement including measures that's where it should go, then add your categories, remember these are just this for the scenarios of thought. Don't agonized over these categories, now you're ready to brainstorm with your team. One approach is to use post-it notes, more about that later, just write the idea on a post-it and stick it next to the appropriate bone. Do not let the team get in a debate about which bone is the best fit, this is a distraction, either pick a bone or write the idea twice. When the diagram is complete, you can take a picture to preserve the work for subsequent use. Here is a customer service example, a precise problem at the head is a good idea, but it can be a general statement of the problem. It can be a product or a process or a service, and the causes can be thought of more as enablers rather than sources of problems. Here you can see a fish bone diagram that identifies the requirements of good customer service rather than a particular problem with customer service. This tool can be a lot of work to set up and use, in small groups, there are often simpler tools for identifying root cause. But if a problem is particularly complex or difficult or if you want the input of a large number of people, this is an alternative to the small group brainstorm. It's called CEDAC which stands for cause and effect diagram with the addition of cards. You can create a large fish bone diagram perhaps on a four foot by eight foot piece of foam core then supply post-it notes, these are the cards. And mount the diagram in an area where anyone and everyone will see it. Anyone walking by can read the diagram and contribute by posting a note. Use this way the diagram must be actively manage, at least once a day you should organize the notes and remove any that are not serious suggestions, you might leaving up for a week. And you can get suggestions from people on other shifts, even from suppliers or customers visiting your facility. You can dig deeper into these possible causes using other tools, such as Pareto Analysis, Matrix Diagrams, 5 Whys or statistical analysis. After a week or when root cause suggestions have run their course, there's another optional step. Move all of the post-it notes to the left side of the main bones, then supply post-it notes of a different color and ask for possible solutions to the previously identified possible causes, this method opens the process up for the ideas of many more people. Cause and effect diagrams may be an effective tool for generating ideas for small or large groups. This is a brainstorming tool, it generates a large quantity of ideas about possible root causes, it does not identifying root cause further analysis is necessarily for that. The team needs to investigate all the ideas and use other means to identify probable causes.
