What is Fishbone Analysis?

Fishbone Analysis or Fishbone Diagrams are a useful visual way to make sense of complex, information-rich problems.  They are a way to combine Brainstorming with Mind Mapping to present Cause and Effect in a structured, easy to follow manner.  Done well, Fishbone will reveal many more possible causes of a problem than traditional written analysis.
 
 
The History of Fishbone Analysis
 
This form of analysis was perfected by Professor Kaoru Ishikawa, one of the 20^th century’s most prominent thinkers in the field of quality and organisational management.  The tool can be used to reveal root causes, uncover risk, reveal organisational inefficiency as well as understand areas of success.
 
Also known as Ishikawa Analysis, Herringbone Analysis, Fishikawa or simply as a Cause & Effect Diagram, the diagrams have a distinctive fish-skeleton design.  
 
 
Fishbone Analysis Steps
 
The process to create a Fishbone Diagram is quite simple.
 
Fishbone Step 1 – Define your problem.  Draw this in a box on the left-hand side of a sheet paper or whiteboard.  From this box draw a straight-line spine horizontally to the right-hand side.
 
Fishbone Step 2 – With your team, identify what you agree to be the major contributing areas to the problem. For example, these could be People, Building, Materials, Systems and so on.  Add each one of these as sub-spine.
 

 
Fishbone Step 3 – Next, brainstorm the causes for these major contributing areas. These are then added as ‘bones’ coming off of each sub-spine.



Fishbone Step 4 – Final Analysis. Your team can now reflect on the chart.  The level of analysis revealed may enable your team to apply solutions and make changes, or it may prompt further analysis in specific areas.
 


Benefits of Fishbone Analysis
 
A good Fishbone Diagram will enable a team to look beyond the obvious symptoms of a problem and reveal a number of previously unknown contributors.  From a position of initial complexity, Fishbone should enable teams to break an issue into ‘bite-size’ chunks and address all of these systematically as part of a strategic plan.
 
Limitations of Fishbone Analysis

• Often Fishbone Analysis can slip into nothing more than poorly structured brainstorming, warping structure around previously held bias or opinion, rather than evidence.

• Fishbone is not especially logical in terms of Cause and Effect.  It tends to categorise causes in a manner that suits the method, rather than reflect the genuine (and complex) interconnections of reality.

• It tends to produce as many irrelevant potential causes as it does relevant ones.  It is hard to prioritise between each, resulting in time and energy being wasted.