Seven Points to Successful Root Cause Analysis (RCA)

Posted 6-20-05
Jinsso Kim

Root Cause Analysis (RCA) is a useful tool for trouble shooting breakdowns and efficiently coming to a solution. I propose the following seven points for successful implementation of RCA that will naturally result in increased profits.

Seven Points For RCA
I. Describe the actual breakdown.
II. Define the physical phenomena of the breakdown.
III. Organize the details of the breakdown by using the '3W2H' (with what, when, where, how,       how much) tool.
IV. Work as a team, respecting each other’s expertise and knowledge, rather than individually.
V. Consider every possible cause of the breakdown.
VI. Verify all logical causes and eliminate all illogical causes.
VII. If determined that the cause of the breakdown was human error, separate that cause from       the physical causes.

I. Describe the actual breakdown.
Describe all observations of the breakdown. Frequently people do not check the breakdown in detail. That is really dangerous way of finding causes, solving the problem. There should be a physical examination of the machines involved and a detailed description of the actual break. In not checking all aspects, there is a high probability of missing the cause. Every aspect must be checked.

II. Define the physical phenomena of the breakdown.
When you are looking for the cause of the breakdown, it is imperative that you define the problem to physical phenomena. For example: If the lamp is off, rather than just stop at problem's phenomena, define 'Lamp off ' in physical phenomena. If you define 'lamp off' to 'electricity can't go through lamp in the circuit', you can get to problem essentially. This is a more exact and helpful description of the problem

III. Organize the details of the breakdown by using the '3W2H' (with what, when, where, how, how much) tool.
Do not make any assumptions when examining a problem. No two problems are exactly the same in nature and cause. Actually, it is extremely rare for the exact same breakdown to occur twice. Look at each problem as if you were looking at the situation for the first time. It looks like even though that cause is different, but their breakdown phenomena looks same. For each problem use: with what, when, where, how, and how much. In answering these questions from a new perspective each time, RCA will be more quickly achieved.

IV. Work as a team, respecting each other’s expertise and knowledge, rather than working individually.
The more input a problem from various perspectives, the better. Everyone will look at the problem differently, so it is to your advantage to seek the assistance of everyone involved in the situation from machine operators, supervisors and managers. One paper company, when their managers joined in an effort to improve their production, thought of a better design for a paper machine. The manufacture of the machine implemented their suggestions with very positive results.

V. Consider every possible cause of the breakdown.
Looking problems in the past may be helpful in determining your cause of the breakdown; however, you should take care in not limiting yourself to past causes. Every possible cause must be considered. All potential causes need to be cleared.

VI. Verify all logical causes and eliminate all illogical causes.
In processing cause analysis, you must consider all causes. It will become clear in the process that some causes will be illogical. Remove all illogical causes after careful examination. You can see they are logical or not by reversing it. Let's look at the simple physical phenomena as an example. ‘Lamp off’ means 'electricity cannot travel through the lamp'. If one of the causes of electricity cannot travel through the lamp is ‘fuse out’, so to find out whether this is appropriate or not, look if fuse is out, electricity cannot travel through the lamp. If it does, you can see that as a possibility of cause.

VII. If determined that the cause of the breakdown was human error, separate that cause from the physical causes.
In the process of team evaluation, it will become obvious that the cause of the breakdown was human error. It is important to separate the human error factors from the physical factors. If there is a human cause, the participation of attendees can be lower. So don't except that possibility. Organize them separately and don't leave out the physical causes.