Management Systems Inc

More business improvement stuff than you can shake a stick at

Ishikawa (Fishbone/Cause-and-Effect) diagram

Posted by isoeasy on May 9, 2006

Ishikawa (Fishbone/Cause-and-Effect) diagram

The Ishikawa diagram (also known as a Cause-and-Effect or Fishbone diagram) is a graphical method for finding the most likely causes for an undesired effect. Kaoru Ishikawa, a famous Japanese consultant developed this method in the 1960s.

Because of its shape, it is also known as the fishbone diagram. Another name for this technique is: the cause-and-effect diagram. The fishbone diagram is a method/tool used in a root cause analysis.The Ishikawa diagram is one of the seven basic tools of quality control, which include the histogram, Pareto chart, check sheet, control chart, cause-and-effect diagram, flowchart, and scatter diagram.

How to make the diagram

Step 1: Take a sheet of paper and draw a box on the right side of the paper. Draw a horizontal line from the left side of the box to the right. Write in the box the effect for which you want to find the causes.

Step 2: Starting from the horizontal line, draw four to six short diagonal lines in the direction the left upper and left lower corner of the paper. These are the main bones of the diagram. Label them with categories you know will span the whole problem space. For example, a business may use: management, manpower, machines and materials (the 4 M's).

Step 3: Identify as many causes under each category and add them to the corresponding category. Detail each cause further (recursively) to the lowest level possible.Analyse this diagram to identify the causes that require deeper investigation. As fishbone diagram identify only potential causes, it may be a good idea to use a Pareto Chart to determine the cause(s) to focus on first. The Cause-and-Effect diagram can be used by individuals or teams; probably most effectively by a group. A typical utilization is the drawing of a diagram on a blackboard by a team leader who first presents the main problem and asks for assistance from the group to determine the main causes which are subsequently drawn on the board as the main bones of the diagram. The team assists by making suggestions and, eventually, the entire cause and effect diagram is filled out. Once the entire fishbone is complete, team discussion takes place to decide what are the most likely root causes of the problem. These causes are circled to indicate items that should be acted upon, and the use of the tool is complete.

Tips:

* Take care to identify causes rather than symptoms.

* Post diagrams to stimulate thinking and get input from other staff.

*Self-adhesive notes can be used to construct Ishikawa diagrams. Sources of variation can be rearranged to reflect appropriate categories with minimal rework.

* Insure that the ideas placed on the Ishikawa diagram are process variables, not special caused, other problems, tampering, etc.

* Review the quick fixes and rephrase them, if possible, so that they are process variables

4 Responses to “Ishikawa (Fishbone/Cause-and-Effect) diagram”

  1. Great beat ! I would like to apprentice whilst you amend your web site, how could i subscribe
    for a weblog website? The account helped me a appropriate deal.
    I were a little bit acquainted of this your broadcast provided vivid transparent
    concept

  2. For anyone not living in a basement apartment, I would suggest finding a place that offers a specific tornado shelter, preferably one underground.
    designer fireplaces denver from Town and Country include the TC36 See-Thru model, which allows for placement in the home so
    that it can be enjoyed in one or more rooms or as a room divider.
    Most people in northern climates are accustomed to this and have the tools and equipment to handle power outages.

  3. Johng97 said

    Because here is a list of multiplayer games is that the leave was asked edfkaekefkae

  4. Johnd514 said

    I really appreciate this post. I’ve been looking all over for this! Thank goodness I found it on Bing. You’ve made my day! Thanks again! dgdcegdcfcbd

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

 
%d bloggers like this: