Root Cause Analysis with example.

Hi folks! Today we will discuss about Root Cause Analysis. It is a very useful tool which is used in different TQM initiatives like Quality Circle, Kaizen, TPM SGA, Six Sigma etc. Many manufacturing companies do the improvement project to reduce waste, manufacturing cost, rejection etc. Impact of improvement project can be seen more if Root cause analysis is done in a right way.  

There are different types of method to find out Root cause analysis

• Why -Why analysis
• Fish bone diagram
• Failure Mode and Effects Analysis (FMEA)
• Pareto Diagram

Why root cause analysis is required.

• To reduce waste
• To Improve productivity
• To Improve Quality
• To Reduce cost
• To Improve safety

Let us understand root cause analysis with an example. There was a famous building in a country.

The color of the building was white. As time passed by, the color of the building changed from white to pale yellow. Administrative people were worried and thought why was the color changing. They decided to do brainstorm session on “why the color was changing”. After discussion they went to their superior for approval. Team suggested that building need to be whitewashed periodically and if they do so, the color of the building will remain white. However, this suggestion was not approved by the senior team due to high budget expense involved.

Team again thought and came out with another idea that entering of pigeons was the root cause and their entrance need to be stopped. Further they examined that pigeons were coming and sitting  on the building and were shitting which made the building dirty and slowly the color of the building changed from white to pale yellow color. So, they told the administrative management that entering of pigeons into the building premises need to be stopped. They suggested second Idea that the building needed to be covered with pigeon net so that pigeons wont be able to enter the building premises, so no shitting thus color wont change. But management rejected the second suggestion too as because covering of the building with net will loose the aesthetic view of the building

Again, the team did the brainstorm session and went to superior and told that if they wash the entire building with good quality of water and cleaning powder, the white color could be retained. But this suggestion was also rejected due to excessive budget. Superior asked them to think simple solution that do not contain much cost.

After that team members were thinking that why pigeons were entering into the building premises. Team observed that pigeons were entering into building premises to eat the insects. Further they brainstormed that from where those insects were entering the building. Team noticed that during the evening time, once pole lamp (near building) was kept on, insects were attracted by the light of the lamp and entered the building premises.

So let’s do Why – Why analysis to find out the root cause!

Why -1 –   Why was the color of the building changing from white in pale yellow color?

                     Because of Pigeons entering and shitting at the building

Why -2    Why were the pigeons entering the building premises?

                    For eating insects.

Why – 3    Why were the insects coming to the building?

                    Because insects were attracted by the pole lamp (when the Pole lamp was kept on).

So root cause was :-  when pole lamp was kept on, insects were attracted and entered building premises which paved the way for the pigeons to enter the building and shitted which ultimately was the reason for the change of the color of the building.

Team members implemented corrective action in this case to switch off the pole lamp during the evening time for some days and therefore there was no accumulation of insects at the building premises. Further team noticed that the changing of color form white to pale yellow color was not happening.