ISHIKAWA’S FISHBONE MODEL

ISHIKAWA’S FISHBONE MODEL 

 “Quality is not an act , it is a habit.” -Aristotle Total quality management or TQM is an integrative philosophy of management for continuously improving the quality of products and processes.

Kaoru Ishikawa

• Karou Ishikawa is best known for the development of quality tools called cause-and-effect diagrams, also called fishbone or Ishikawa diagrams.

 These diagrams are used for quality problem solving.

• He was the first quality guru to emphasize the importance of the “internal customer,” the next person in the production process.

He was also one of the first to stress the importance of total company quality control, rather than just focusing on products and services.

 • Dr. Ishikawa believed that everyone in the company needed to be united with a shared vision and a common goal. He stressed that quality initiatives should be pursued at every level of the organization and that all employees should be involved. • Dr. Ishikawa was a proponent of implementation of quality circles, which are small teams of employees that volunteer to solve quality problems.

 

Real Life Example Boston Public Library

 Objectives The main goal of the Fishbone diagram is to illustrate in a graphical way the relationship between a given outcome and all the factors that influence this outcome.

The main objectives of this tool are:

• Determining the root causes of a problem.

• Focusing on a specific issue without resorting to complaints and irrelevant discussion.

• Identifying areas where there is a lack of data.

 Field of Application The Fishbone diagram could be applied when it is wanted to:

• Focus attention on one specific issue or problem.

• Focus the team on the causes, not the symptoms.

• Organize and display graphically the various theories about what the root causes of a problem may be.

• Show the relationship of various factors influencing a problem.

• Reveal important relationships among various variables and possible causes.

• Provide additional insight into process behaviors.

 Fishbone Suggested Categories Service Industries (The 4 Ps) Manufacturing Industries (The 6 Ms) Process Steps (for example) Policies Procedures People Plant/Technology Machines Methods Materials Measurements Mother Nature (Environment) Manpower (People) Determine Customers Advertise Product Incent Purchase Sell Product Ship Product Provide Upgrade

 Analysis of Ishikawa Diagram

  brainstorming session to generate potential causes can come up with many potential causes of the effect in question.

 The team has to then analyze the potential causes to decide where to focus their attention.

  The first stage is to highlight those that causes that are likely to be the main contributing factors, an easy way to do this is rate each cause, depending on how detailed you want to be this can be as simple as hot, warm or cold or rating from 1 to 10.

 The next stage is to look at the remaining “hot” causes and define actions to resolve them; these actions can then be rated against both their ease of implementation and the expense of implementation. The team first implementing those actions that are both easy and inexpensive!

 The fishbone diagram and the data can be revisited on a regular basis as time passes to see how actions taken affect the problem in question.

Thus you can drive continuous process improvement.

 BENEFITS

• Helps determine root causes

• Encourages group participation

• Uses an orderly, easy-to-read format to diagram cause and effect relationships

 • Indicates possible causes of variation

• Increases knowledge of the process by helping everyone to learn more about the factors at work and how they relate .

• Identifies areas for collecting data