Fishbone Diagrams

Another great way to organize your ideas around a rout-cause or cause & effect puzzle in a structured way is the Ishikawa diagram, aka the Fishbone diagram because of its shape.  It is a more structured way than just asking yourself why 5 times. You can use this in team to flesh out the reasons behind a problem in front of a whiteboard or you can make it by yourself to organize your thoughts about the causes of a problem.

Pre-filled

For some problem areas certain categories have been proposed in the past:
  • transactional categories
  • Manufacturing categories
Typical categories (the main bones in the diagram) for manufacturing are (the 6 Ms):
  • Machines
  • Methods
  • Materials
  • Mother Natrue (aka Environment)
  • Measurements
  • Man Power (aka Personnel)
And these are typical trasactional or service industry categories:
  • Systems
  • Processes
  • Forms
  • People
  • Policies
  • Place
Note that in the above many causes are badly formulated. You should avoid using cause that resemble “lack of …”, “Too few/little …”, because these are not tangible causes.  You should come up with measurable causes (e.g. only “20% of the staff is trained”).  For more on this watch the Video Tutorial we refer to.

Free-format

Of course, if those categories don’t suit your needs, you can choose your own. You can remove any of the categories that don’t make any sense for the particular problem you’re looking at.  This works best in a brainstorm format. The downside is that you loose time coming up with good categories and that you might also not come up with the appropriate categories.

Combined with the 5 whys

Now once you’ve identified some of the root causes of your problem, you can continue by applying the 5 whys approach, to really go into the details of the root cause.

Video tutorial

Here’s a very instructive video from leansixsigma on the subject: