Cause and Effect Analysis Graph

Article on cause-effect analysis.

Let us start with cause-effect diagram. It is a visual representation used to find out the cause or causes of a specific problem. It is a diagram that maps one or more causes to one or more effects. Instead of jumping to some actions to solve the problem, the cause-effect diagram allows exploration of possible causes. This may lead to a better solution to the problem. Cause effect diagram is applied in defect correction in products and services. Now, let us see the cause effect diagram that it looks like the bones of a fish That is why it is called the Fishbone diagram or Herring Bone diagram. Other names of this diagram are cause effect graph, ishikawa diagram or fishikawa. The effect or the problem is put in the head of the fish. The categories are put as branches from the backbone.

The causes are put as branches of the appropriate category. Any sub-cause is put as a branch of that cause. Now, causes are grouped into these cause categories. People means the workers’ physical and mental labour, their experience and training. Methods mean processes and include procedures, rules and regulations. Machines mean the technology used and include equipment such as computers and tools and maintenance of the equipment. Materials mean ingredients or raw materials consumables and input data. Measurements mean readings or process data. Environment means temperature, pressure, time, humidity, dust location and Mother Nature. You can remove any unneeded category and add any needed category. Now, let us learn how the cause-effect analysis is done with the help of an example. First, the stakeholders get together as a group. The group identifies the problem or effect. Say, the application is slow. Now, the facilitator writes a problem statement as a question. He or she draws a diagram with the effect. Then adds cause categories.

People, Methods, Machines, Materials, Measurements and Environment. These are the same categories that we saw earlier. Now, the group brainstorms about possible causes of the effect. The facilitator puts each cause in the appropriate category. For example, a cause for slow application could be a small server. This is added to the Machines category. Another possible cause could be that the application source code is not optimized for performance. This is added to the Methods category. Another cause could be wrong server configuration. Now, the group asks “why” about each cause. This leads to sub-clauses. For example, the server could be configured wrong because of lack of training to the system administrator. The group analyzes and prioritizes the causes. Then, the facilitator highlights the top cause, say, wrong system configuration. Next, the group validate the top cause. If they find that it was a real cause of the effect, they address it as a team so that the cause is removed. Else the group moves to the next top cause in the cause effect diagram. So, in this tutorial we learned about cause effect diagram.