Root Cause Analysis: The 5 Whys Technique and Its Limitations

Root Cause Analysis: Definition and Purpose

Root cause analysis is a popular problem-solving technique that seeks to identify and respond to the deeper causes of a problem as opposed to only those that are visible on the surface (Okes, 2009). It allows one to look deeper into a problem in order to determine what the underlying causes are and to fix these issues before the problem escalates to an even bigger one (Okes, 2009). In doing so, one deals with the problem once and for all. Once the root causes are addressed, the chances of recurrence are very slim.

The questioning-to-the-void technique, commonly referred to as the 5 whys technique, is one of the three approaches of root cause analysis. It basically entails asking the question "why" five times in order to understand the exact nature of a problem (Anderson, 2009). It is believed that by repeating the question "why" several times, one is able to peel away the surface causes of a problem and ultimately identify the root cause. Once the root cause has been identified, an appropriate counter-measure that effectively addresses the root cause can be determined.

The 5 Whys Technique Explained

Consider the case of a printing shop that was supposed to have a client's leaflets printed and delivered but failed to do so in time. As a result, the client refuses to pay for the materials. Applying the 5 whys technique:

The Problem: The client has refused to pay for leaflets delivered.

Practical Application: Printing Shop Case Study

Why? The leaflets were delivered late and were therefore not used for their intended purpose.

Why? The printing job took longer than the staff had anticipated.

Why? Printer ink ran out in the course of printing.

Advantages of the 5 Whys Approach

Why? A lot of ink had been used up on a large order that was executed right before the order in question.

Why? There was not enough ink in stock, and the staff could not order the same quickly enough.

Root Cause: Delayed delivery of ink, leading to slowed-down or stalled processes and making it difficult to complete orders in time.

Limitations and Criticisms

Counter-Measure: Find an ink supplier who can make deliveries on very short notice.

Based on this illustration, several advantages of the questioning-to-the-void technique and, by extension, root cause analysis become evident. First, it is easy to use and apply, especially if the assessor has a sense of what the causes of the problem are likely to be (Okes, 2009). Moreover, it is highly flexible and readily fits into a number of other common business processes. For instance, the 5 whys technique is used in quality improvement in the analysis stage of the Six Sigma process and for identification and elimination of wasteful practices in lean manufacturing.

Thirdly, the technique ensures that problems are resolved once and for all, and that no further costs are spent in addressing the same problem in the future (Dew, 2002). When a root cause is correctly identified and fixed, the likelihood of the problem recurring drops significantly, resulting in long-term organizational savings.

Despite its inherent advantages, root cause analysis may be unattractive to most organizations for a number of reasons. First, it provides no surety that the issue identified as the root cause is actually the root cause (Anderson, 2009). In other words, it does not provide a basis for the assessor to test the sufficiency of the factor identified as the root cause. For this reason, multiple people using the technique to evaluate the same problem are likely to arrive at totally different root causes, depending on what each assessor identifies as causes (Anderson, 2009).

Moreover, the technique assumes that all problems have a single underlying cause, which may not always be the case, especially in very complex problems likely to have multiple contributing factors. Toward this end, root cause analysis may not effectively resolve technical problems with more than one sufficient cause, which is dangerous given that most organizations today operate on the global scene, and most problems are therefore too complex to be narrowed down to one sufficient cause (Anderson, 2009).

A third reason why organizations may avoid root cause analysis is that the method may not be as simple as it appears, especially if the assessor lacks technical training to prevent the evaluation from being affected by deductive reasoning (Anderson, 2009). What happens in these cases is that the assessor asks "why" the first time and notes all the possible causes. He then asks "why" again to identify the factors underlying each of the identified causes. At this point, he is likely to begin relying on deduction and will end up with multiple causes that may appear equally important (Anderson, 2009). This means that the 5 whys technique may only be effective in the resolution of moderately difficult or simple problems, not critical and complex issues likely to have multiple causes. In such cases, the cause-and-effect technique, which has a much broader scope, may be more effective.

Conclusion: Appropriate Use and Context

The root cause approach, in as much as it is relatively simple to apply and helps to address the very root cause of the problem, may not be very effective in evaluating problems in this age of globalization—particularly because organizations have relatively complex structures and cultures, and the resultant problems are likely to be too complex to be associated with just one single sufficient cause. It should only be used as a supplementary method of evaluating simple problems.