Cause and Effects Diagram
From: M. D. Anderson Department of Performance Improvement
Date: January 15, 2008
Cathy Modaro: Hi I'm Cathy Modaro, I'm one of the Systems Improvement Specialists in Performance Improvement, and today I'm here to talk to you about some of the common pitfalls that you may encounter as you're doing a cause and effect analysis. As a reminder I have gone over some of the steps that you would need to do a cause and affect analysis, also known as a fishbone diagram. I'm just gonna go over the steps briefly but if you have any questions about it, make sure that you contact your coach who will be able to help you with this particular tool.
The first thing that you're going to do is draw a blank fishbone diagram. Put your problem statement on the right hand side of the diagram where the head of the fish would be. Add your category headers which can include things such as people, policy, process, equipment, supplies, and facilities. Draw your lines from the category headers to the spine of the fish, and then you would brainstorm the causes and add the causes to each of the categories then you have your completed fish bone diagram.
Using this cause and effect is an excellent way to determine your root causes and all of your different causes for the problem statement. But I want to warn you there are a few pitfalls; the first one I want to talk about is that the cause and effect analysis is not a substitute for data.
There are no measurements with the data that you're putting on the fishbone diagram. These can be anecdotal stories, it might be something that happened to one person one time, but they're gonna remember it for a long time and that you need to make sure to capture it on the fishbone. And then also it does not differentiate between your common causes and your special causes. You need to make sure to examine all your causes, see which ones are tied together, try and figure out which ones happen on a regular basis or which ones might not happen on a very regular basis. So as a solution for that what I would like to recommend is that you do continue with your defined data collection, make sure that you have that in place and you collect your data to look at your baseline information.
Another option is to use multi voting to select your high priority problems and I will tell you a little bit more about multi voting in a few slides. A second common pitfall that could occur is that as you're doing your cause and effect diagram you might be actually identifying symptoms before the problem has been thoroughly analyzed and stated. Hopefully you're gonna be doing a flow diagram for your process and one of the things that I would recommend is that as you're doing your flowchart you would capture the problems with each of the steps and put the problems directly onto the fishbone.
A third common pitfall is that sometimes you may limit the theories to those that are identified. You're gonna be doing your brainstorming session and you may not have all the correct players in the room and you'll find that out later on as you start to uncover other causes that you did not include in your diagram. And what I would like to give to you as a solution for that is to make sure that you continue to update your fishbone diagram and at some point you probably will turn the causes from the diagram into an issues list that you're gonna prioritize. What you need to do is make sure that as you continue to uncover causes, make sure to include them on your issues list.
After the common pitfalls what I'd like to do is go back to the multi voting. This is a really good way for your team to be able to prioritize the issues that you've just generated because chances are you have a lot of causes. Now how do you know which ones to focus on? Multi voting is an easy solution everybody in the room would participate. You can assign each person ten points or something along that line, you could do with five, you could do with twenty depending on how much time you want to spend on it, each person would get to assign their points to the causes that they feel are the most important.
After each person assigns their points you could go through for each cause and count up the number of points that it has. That's gonna give you a rank order of all your causes, you would put them onto a priority list and you would also make sure that you leave every cause on the list. You're gonna have some causes that will not have any votes, that doesn't mean that you don't want to address it, it just means that it's not as high of a priority.
As you continue with your issues list you might go through and decide that no action is required for that cause and it can bump to the bottom of the list but you definitely need to make sure that it stays on the list so the team and everybody else who looks at the issues list can realize that that cause was addressed and no action was required for it.
Now I have something fun for you to think about. Did you ever wonder why a fishbone diagram is called a fishbone diagram? Well Dr. Ishacowa who invented this particular cause and effect methodology, he was from Japan where one of the main staples of food is fish so in his eyes when he looked at his diagram he came up with a fish and called it the fishbone. But if Dr. Ishakawa had lived in Australia, he might have been more likely to call it a shark diagram and he might have put the category headings on the fins and put the effect or the problem statement over by the mouth of the shark. Another option to look at is that if Dr. Ishakawa had been a gardener he might have called it a weed diagram and he might have realized that all of the root causes have to be addressed to get rid of all the weeds or dandelions and a third option is also if Dr. Ishakawa had been a forest ranger he might have looked at it as a tree and looked at each of the branches as the category headings and the problem statement on the top of the tree.
So that's just something fun that I'd like to leave with you. And now we're gonna go back to Duke and Tina.