What Happens When You Swallow an Ishikawa Fishbone?

Answer: You spit out a solution.

In my last blog, I wrote about the Lean Six Sigma tool: “Poka Yoke” In it, I introduced the Ishikawa's Fishbone Diagram, a unique but important Lean Six Sigma tool used in determining the "root cause" of a problem.

(Picture courtesy of marketergizmo.com)

To summarize, the diagram is actually a picture of a fish skeleton. It is divided into two parts: the left, body, represents the CAUSE; and, the right, which is the head represents the EFFECT (or outcome) that is either positive, neutral or negative.

If you look at the picture, the body which has spines on ribs is divided into four parts: labor, equipment, material, and methods. The tail represents environment which I believe is the most important component. (If you read the rest of this post, you'll see why.) 

All problems can be identified through this simple diagram, a systematic way of asking questions and resolving problems.

To illustrate, a near serious problem occurred in the oil fields where I once worked.  An employee nearly cut into a live gas line. Had this happened, his “chop saw” would’ve breached the pipe, sparked, and exploded.  Highly pressurized with natural gas, the explosion would have cost millions of dollars and lives lost.

This incident was averted when an alert employee, not a supervisor nor foreman, issued a “stop work”. 

When the crew was set aside and interviewed, the investigator asked questions regarding who was involved, equipment, material and processes.  He collected and reviewed all SOPs (Standard Operating Procedures), Job Safety Analysis; Control of Work; and Hazard and Work Instruction Documents and asked if each individual followed the steps outlined in the documents.

The interview process took several days before a root cause was determined: the supervisor who was assigned first watch was called out. The foreman who was assigned “second watch” picked up his cell phone and, consequently, distracted from his duties. First (or second) watch is a term that assigns a person to observe from a vantage point and verbally issue instructions and warnings.  

The crew member with the saw did not know the foreman’s attention was averted.

When the incident occurred, the crew member was harshly reprimanded; however, after it was investigated and report submitted, a combination of factors contributed to the root cause. As I explained, the Ishikawa Fishbone tail, or "environment" represents anything and everything outside of the four components that affect outcome, in this case being called out and answering a cell phone at a critical time.

SOPs were modified to include a section where supervisors are not to leave the site or foremen not to respond to cell calls during critical phases.  

So again, what happens when you swallow an Ishikawa Fishbone?