Fishbone Diagrams

There are many ways to draw a Fishbone Diagram including freehand, with flowcharting software or in a spreadsheet.  I find freehand is often best but the illustration below was drawn using a Microsoft Visio template (as my hand-drawn versions are not really fit for wider publication).

Start with stating your problem at the head and draw the spine.  Then add the main “ribs” – the number depends on the situation and there are several mnemonic rules.  A common one is the 6M – Man (as a species, not a gender), Machine, Method, Materials, Measurement, Milieu (aka Environment); this is good for manufacturing situations.  Amongst alternatives are  the 4S – Skills, Supplies, Systems and Surroundings; or the 4P – People, Places, Policies and Procedures.  These latter two are better suited to service situations.  Then draw in the various causes, causes of causes, etc.  It can get crowded.  One technique useful here is the 5-Why – ask why something happens, then why that happens, and again and again… until you get to a point where there is no further answer.  You’ll usually reach that point within 5 iterations but don’t let the number become a constraint.  You might also want to include an occasional “How?”  The aim is to drill down until you get to the root cause each time.

My illustration here relates to our example of being late on some work and could have been used as a starter for the Tally Sheet.  It’s probably overkill for this situation but should illustrate the format (and doesn’t really need the fish shape around it – but Visio includes it for effect).