fishbone diagram

How to Draw a Fishbone Diagram


The “Fishbone Diagram” is simple tools used for potentially understanding the root cause to a problem. It resembles a fish’s skeleton with head left untouched. It is also called the “Cause and Effect Diagram”.

The head of the fish represents the “Effect” (or the Problem which we are trying to find the root cause). The bones coming off the main back bone are high level “Causes” that branch off to sub-causes and potentially to root causes.

  • Create the head of the fishbone diagram which lists the problem or issue to be investigated. Be specific about how and when the problem occurs.
  • Create a backbone for the fish (straight line which leads to the head).
fishbone diagram

Now we draw the main bones that come off of the back bone. There are two different ways we can categorize these bones:

  • These bones could be the main causes of the effect (or problem) which we can drill down further to discover root causes, or
  • We can use generic categorizations (like the ones below)
    • Methods (for example; SOP’s, work instructions, OJT)
    • Machines (or equipment, databases, IT assets)
    • People (labor or manpower)
    • Materials (actual materials or information)
    • Measurement (for example: KPI’s, exception reports, production expectancies)
    • Environment (for example: noise, temperature, culture)
fishbone diagram
From the main bones we know dig deeper into the potential contributing causes.
fishbone diagram
We keep asking “Why do the contributing cause happen?” to dig deeper in the potential root causes.
fishbone diagram

It is very important that the potential root causes are ACTIONABLE ITEMS! Actionable items are problems that we can implement a tangible fix. For example, one of the root causes to the effect of “Employees are average of 7 minutes  late to work over a 30 day period” is that the metric of “on-time” has not defined in employee handbook.The fix to this is tangible (to define “on time” and subsequently to measure timeliness).

What did you think? Did this article help you and your team to develop an effective Fishbone Diagram? Please share your thoughts in the comments below.