Some are inclined to use this root cause analysis technique because of its simplicity. Be in the know however, that it is also faulted for its limited capability to explore other areas.
Nonetheless, the 5-why method was popularized by the Toyota Company because they have found it effective, largely because of the ease by which it can be adopted.
If by the fifth question or thereabouts, no more why questions are prompted, the last answer is deemed as the root cause. It is appreciated in this aspect, since the root cause could be established without the need for data segregation and statistical analysis.
- On the other hand, if by the fifth question, the answer derived leads to faulty reasoning or is not as intuitive as expected, it is suggested that another rood cause analysis technique be applied.
- The 5-why method is supposed to follow a linear-progression of logical reasoning, and the process works by commencing with the outcome and continues by tracing back the sequence of actual events down to its origination. Still, the process can still go into details and proceed using more than five why questions for as long as the sub-causes reveal relevant information.
- This RCA technique is widely used in the health care industry where patients have concerns or complaints that need to be immediately addressed. The typical frameworks it can effectively broach are the day-to-day service activities related to:
1. Improvements due to loss of quality or regression of production capacity, usually as an approach to lean manufacturing. However, the analysis has to start with the initial phase of data gathering via a Pareto chart. Take note that the data should be based on facts since the aim is to arrive at a quick-solution. Other aspects of lean manufacturing to which this root cause analysis technique applies are: (1) breakdown or inefficiency of equipment, (2) time loss, and (3) waste reduction toward zero-waste attainment.
2. Investigate incidents that led to serious injuries or accidents. The analysis makes use of the known 4-P’s of information, namely people, paper, parts and position as gathered from separate interviews and available resources. Here, questions asked are still open-ended in order to collect the most confirmed version of the accident. “Why" questions are asked last.
3. To assess environmental incidents in order to formulate counter-measures, such as groundwater or soil contamination, indoor or outdoor air emissions and like-incidents that can severely impact the environment.
Once the root cause is established and the solution or counter-measure is put in place, it is always the best practice to test whether the latter’s application reveals positive results.