How to Use a Fishbone Diagram

The fishbone diagram, which also goes by a couple of other names like the Cause and effect diagram and the Ishikawa diagram is one of the seven basic tools of quality management. It has wide ranging applications in almost all six sigma projects. The Fishbone diagram is a simple but highly effective tool in problem solving.

How We Usually Solve Problems: The management in every organization is in charge of solving everyone’s problems. But as we know they are not very efficient at it. This is because of their lack of knowledge that a problem does exist. Also once they realise the problem, they may not have sufficient insight to solve the problem. It is for this reason Fishbone diagrams suggest that cross functional teams be used. Cross functional teams include workers, technical staff, management, support functions staff etc. Only the use of cross functional teams can make brainstorming a success with or without a fishbone diagram.

To be Used in Teams at Brainstorming Sessions: Once a cross functional team has been selected to solve the problem a brainstorming session is called. However instead of the usual brainstorming a Fishbone diagram is used. This helps get structured inputs from various members of the organization.

What Exactly Does a Fishbone Diagram Do ?

The fishbone diagram is called a fishbone diagram because it does look like a fishbone. So how exactly does it help in brainstorming? Here is how. An issue is listed at the far right hand corner of the diagram. A central line is drawn from the left pointing towards the issue. This line then branches out into several lines, each of which represents a category of problems.

Firstly by categorizing problems, we understand the fact that they might have similar root causes. Hence we can solve the issues more effectively and by utilising minimal resources.

Categories Give Structure to Thinking: Now, Brainstorming can be done in several ways, there is no need of a Fishbone diagram to do so. However, Fishbone diagrams help in giving structure to the thoughts. This is because Fishbone diagrams have pre-defined categories. Therefore when a participant is trying to brainstorm they have a more specific way to look at the problem. For instance, in a brainstorming session people may be asked their views on how materials mismanagement is leading to delayed deliveries.

Only One Issue per Diagram: The flipside of a Fish-bone diagram is the fact that there can only be one issue per diagram. However, in quality management it is a known fact that cause and effect are seldom present in one layer. Hence the use of fishbone diagram may become problematic in certain cases. This is when one issue leads to another and another. Instead of one fishbone diagram, several others may be required and the whole process of problem solving may become exceedingly complex.