5Why implementation theory training      Jr-Lung Chen   2014.2.12

I am very grateful to the Molex Mr. Yang’s Five Why course, a one-hour session like short 10 minutes, easy-to-understand content relevant to real cause and root cause, and offered by QCC consultant in 2013, letting me almost understood in 10 minutes.  

Real cause: immediately resolved to know the answer, unable to be analyzed by Five Why, and similar to QCC’s cause.

Root cause: system factors (different varieties) shall be analyzed by Five Why. Root cause is similar to QCC’s phenomenon.

To compare with Yang’s and consultant’s ideas, it proves that phenomenon is not equal to cause, and vice versa. Many events may occur with only one cause, but the phenomenon leading to the cause can be many types. The session would like us to distinguish well between cause and phenomenon, and then use five why to effectively prevent an event occurring.

After the session, I had a chance to apply it in practice.

Discipline 0. Prepare for the 8D Process: if 8D can be applied for the prevention

0-1 wire cutting machine cannot function well. A machine manufacturer would be asked to handle a severe problem. Extra time and money is required

Discipline 1. Form the Team: Shihchin Li, Anhsien Tseng, Chihlung Chen, Jinnefer, and Lyzl

1-1 Personnel, usually using wire cutting machine, attended the team.
Discipline 2. Describe the Problem: quantify the problem as clearly as possible

2-1 Getting back to work after completing Five Why session at 11:00, Jinnefer responded that machine B was not able to normally thread to manufacture—before the morning session, it was in the normal working state).

Discipline 3. Contain the Problem: action to resolve the D2,,,,,,,,,, and so on.

    3-1 First gut reaction: checked an electric conductor and its latest replacement time, and carried out 5S management.


3-2 After the electric conductor was replaced, the situation could not be handled. Checked copper wire into the lower bearing.

Discipline 4. Identify the Root Cause:

    4-1 Took apart the lower system and found that rotation could not work properly—it certainly was not able to normally fed the machine wire.

Discipline 5. Formulate and Verify Corrective Action:

    5-1 Shihchin Li, Anhsien Tseng, Chihlung Chen, Jinnefer, and Lyzl discussed, reviewed, and concluded that:

  1.Machine was not cleaned up often. So machine washing will be once every two weeks instead of three.

  2. Checked the carbon brush inventory to avoid consuming them but unable to be filled up in time.

Discipline 6. Correct the Problem and Confirm the Effects:

  Cleaned, replaced, and reinstalled every parts, and re-aligned UV axis for successful wire feeding
Discipline 7. Prevent the Problem

    After processing and assembling the parts and testing and starting the machine, it was completely fixed. A machine manufacturer didn’t need to handle it. Machine cleanliness and carbon brush consumption had been noticing at any time if wire feeding issue happened again.   

Discipline 8. Congratulate the Team

If following and finishing the steps above, and the issue had been improved, the team was able to be dismissed. 

The process above lets me deal with the future problems quicker and more effectively as well as able to produce feedback to every future 8D report. Whether new staff training or other colleagues’ questions, this will reduce repetitive problems and efficiently detect and solve them.