How To Use A Fishbone Diagram To Avoid The One That Got Away



Do you remember the last time your friend told you about the biggest fish that he or she ever caught? (It was immense!) Of course, there is no real evidence of the fish. It’s not like there was a photograph or something that you could see…but, as your friend will tell you, it was one of the biggest fish they’ve ever seen. Here, we discuss an important quality improvement technique that can help you avoid being caught up believing in that biggest fish story ever told.


A Fishbone Diagram Helps


Have you ever heard of an Ishikawa diagram? Guess what. It’s also called a “fishbone diagram”. The Ishikawa diagram helps you identify those factors that you think correlate with a certain outcome. Sometimes it’s called Y=f(x). This gives the idea that the outcome you’re looking at, Y, is a function of different variables in some system. Recently, a quality improvement team I helped used this fishbone diagram to avoid being caught up in a fish story like the one your friend may have told you. Here is how they did it.


Avoiding The Bait With The Fishbone Diagram


This particular team was interested in how long it took them to bring on new physician hires, because delays were really impacting the system.  There are lots of factors involved and the team used an Ishikawa diagram to label all those factors that they think played an important role. There were a whole slew of factors that the team thought could influence how long it took to bring on new hires.  The team could have taken the bait (sorry for the pun) and simply tried to adjust the most obvious factor they intuitively thought correlated with time until a new physician hire got to work.  Instead of falling for that fish story (yes, I’ll say it:  hook, line, and sinker…) the team decided to use data to help them see what correlated with time until a new physician got to work in the system.


They then went on to label the factors as ones they could control (with designation “C”) and ones that they felt were noise (N, or something they couldn’t control). They then collected data prospectively on the next providers who they brought on board. After the team had all the data, they used a multiple regression model to turn their fishbone diagram into powerful conclusions.  (Read more about using a multiple regression with and Ishikawa diagram here.)


Reeling In Some Conclusions


In this case, the team learned that the only factor which reached significance in the model of the factors contributing to total time until the provider started was the variable “amount of time from when the state medical board received the providers completed application until it went before the board for acceptance” which they called board receipt to presentation.


This is an important learning point for the team. It turns out many of the other things they thought correlated didn’t seem to reach significance and, so, working to improve those other factors probably wouldn’t influence time until the physician got to work. This important fact allowed the team to refocus on how to decrease that important time from submission of an application to the board until final board approval.


How did the team do it?  They broke down the factors that often made the board have to go back and forth with them as a healthcare system. They looked into what prevented an application from being turned in cleanly and immediately going to the board. Then they looked to decrease cycle time from when the board asked for more information until the board representative received the information it needed. They looked at how to decrease the number of incomplete applications and how to answer questions better (and faster) so that applications could be put before the board more quickly.  The team knew where to fish because it knew where to spend its time concentrating.


Now Go Try It Yourself


Now you see an important way that a fishbone diagram can be used to avoid a fishing story filled with red herrings. One way to avoid misdirecting effort and time in a quality project is to use the fishbone diagram along with a multiple regression.  We hope you find these two tools more useful together and best of luck on your next fishing trip.