The Ishikawa diagram, more commonly known as the fishbone diagram (because of its shape) or the cause and effect diagram (because of its purpose) is an excellent tool for ensuring that there has been a comprehensive consideration of all of the potential root causes to an issue before a group focuses in on a likely subset.
The problem or effect is specified in the ‘head’ of the fish (a box on the right of the diagram) and participants use the themes (titles at the ends) of the ‘bones’ of the fish to brainstorm possible causes to that effect. The structure of the diagram makes it easy to see where particular areas of thought may have been neglected or over emphasised.Many unstructured approaches to solving problems tend to go round in cycles as one pet theory after another is tried. The Ishikawa diagram helps to place all the pet theories in context from the outset, and to establish a more methodical process for identifying the real issue.
There are commonly three different variations of the diagram: Blank (with blank legs to accept whatever themes you choose); 4M (which takes the standard themes of Manpower, Materials, Machinery, and Method); and PEMPEM (Plant, Equipment, Materials, People, Environment, Methods).
One key charachteristic of a well considered Ishikawa diagram is that it should have stupid (perhaps humourously so) ideas on it. The reason for this arises from a combination of factors:
- As a well facilitated exercise, everything that is voiced should appear on the diagram
- Part of the reason for this is that ‘daft’ ideas take our minds to different places, and can enable us to see things we might otherwise miss
- Where only sensible ideas appear, it is quite likely that people have not moved their thinking out of conventional channels (or have filtered it when they did) and therefore it is more likely that the end result is missing certain perspectives
Once a sufficiently wide range of potential causes has been identified, it is a matter of researching the causes to gather sufficient data/evidence to prove or disprove them.
However, undertaking this research for all of the listed potential causes is both inefficient and impractical, and so it is best to begin by refining the list down to a few preferred suspects. This can be done by voting with sticky dots (or the stamp tool in a virtual meeting) or via discussion. The preferred causes can then be tested, and if they fail to show a relationship, and second wave of possible causes can be identified, and so on.
The following links provide more information on the tool
Clicking the instant template below will open it up as a live interactive tool in your browser. Simply copy its URL from the address bar on the page that opens and share it through your meeting chat with your team. They will instantly be able to participate with you by: adding their thoughts via sticky notes; seeing all that’s going on, and moving things around. For more on instant templates, click here.
A very useful variation of the Ishikawa diagram, is to flip it 180 degrees horizontally, placing the head on the left of the diagram, and then to write in the head an intended change or solution. The legs of the diagram are then used to explore the potential implications (good and bad) of implementing that solution (different coloured pens or dots help identify which are which)
Called the Solution-Effect diagram, or Reverse Fishbone, it helps people think through the potential consequences of change, and to plan for them: maximising and leveraging the positives, and avoiding or mitigating the negatives. As with the normal Fishbone, it is useful to prioritise where you will focus your attention within it, rather than try and do everything.
Again, clicking the instant template below will open it up as a live interactive tool in your browser, as above.
Track your progress to ensure the efficacy of this strategy.