Cause and Effect Diagram

Quality Management has gained utmost significance in today’s business. It is of paramount importance for organizations to deliver a defect free product to customers, built in the most efficient manner, thereby ensuring customer satisfaction. This in turn ensures maintaining both the top lines and bottom lines of businesses.

Cause and Effect Diagram, alternatively also known as Fishbone Diagram, was conceived by Japanese Quality Management Guru Ishikawa-san. This technique is a very simple yet one of the most effective techniques and tool for determining root causes of various problems/defects we face in production or in the projects.

Cause and effect diagram has become now a very commonly used technique for analysing any kind of organizational problems, not necessarily only quality related problems. 

The fishbone diagram is a visual way of analysing and capturing the cause and effect. It looks like a fishbone. The mouth or head of the fish depicts the problem, and various bones depict the possible root causes. Root cause analysis very often is done as a brainstorming activity involving the team members.  The team engages in analysing the each of the problems/defects trying to find the root causes of these problems. This needs to be done in a structured manner and it is important to understand all the causes contributing to the defect or the problem. 

The above diagram presents a sample example of a cause and effect diagram. Below are the steps which are to be followed for using this technique effectively.

1. Typically a chart paper or a white board is used for capturing the findings from brain storming session.
2. Describe the problem statement clearly ensuring the all parties involved agree on the same. Let the problem be defined in detail, all who contribute to the problem must be identified; details of where the problem occurs must be listed. The problem can be written at the end of the central line at the mouth of the fish.
3. Identify the major factors that may be relevant for this problem. Some of the generic categories could include “Methods”, “People”, “Machines”, “Environment”, “Materials” and may be other relevant categories.
4. For each of the factors, identify the underlying root causes. The moderator will continue to ask “why” the problem has occurred. And keeps noting the inputs appropriately alongside the major factors. Continuously asking “why” this has happened until the team exhausts all reasons.
5. Analyse and brainstorm to identify the most important root causes, by prioritising them

In order to make this technique effective, we must involve and engage all parties involved in the entire process and get their skills polished with robust PMP certification training.