The "secrets" of root cause analysis

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This successful problem solving and continuous improvement methodology, identifies the root causes of a contingency, going beyond its superficial effects, showing at what exact point the processes or systems failed, and preventing future similar crises.

Those who have faced an emergency, in their personal or work life, know that it is much more effective to prevent and systematically solve problems, than to dedicate themselves only to treating their symptoms and “controlling fires”.

This principle is precisely the theoretical basis of the “Root Cause Analysis” or RCA, a widely used method to solve problems or contingencies, starting from the identification of their underlying or deep causes.

Although we carried out RCA’s after the contingency occurs, their methodical, deep and comprehensive nature allows, at the same time, to draw relevant methodologies and action plans, which help to forecast and prevent new negative events.

This characteristic, added to the fact that RCAs can be applied constantly, make them a valuable tool for continuous improvement processes; helping to optimize and consolidate the vision and strategic mission of any company or organization.


– As the name implies, the primary objective of an RCA is to discover the root cause of a problem or event.

– At the same time, we must understand how this situation can be repaired, compensated or resolved, from the in-depth analysis of the underlying problem within the same root cause.

– Finally, we must apply everything learned in this analysis in order to prevent future problems; or, to design and apply new successful contingency strategies.


In principle, RCAs offer the advantage of having a simple structure, although practicing them is not always an easy task, since there are many tools, processes and philosophies that allow conceiving, designing and implementing them.

In this sense, the main recommendation is to systematize the RCAs, according to the characteristics of each productive sector, organization or area where they are applied.

International experts rank RCAs according to five source variables: safety, production, processes, failures, and systems.

Safety They come from the field of safety, health and prevention of occupational accidents.

Production They originate from quality control for industrial manufacturing processes.

Processes They correspond to a variation of the production RCAs, but with a scope specifically defined for business processes.

Faults They arise from the direct practice of fault analysis, as used in engineering and maintenance tasks.

Systems For more strategic applications that require the combination of all the other variables, incorporating concepts from change management, risk management and systems analysis.


The easiest way to justify a root cause analysis is to solve common problems. But, how to do this effectively? A first approach is to take, as a reference, cases from everyday life. For example, if we feel sick and vomit, we go to the doctor to ask him to “find the root cause” of our illness; or if our car suddenly stopped working, we ask the mechanic to “find the root cause” of that malfunction.

In the same way, we can project this scheme to a company or organization. If it has a bad performance problem, in a specific area, we must try to find out “the root cause of that problem”, to solve it and try not to repeat it.

In theory it sounds easy, however, RCA requires going beyond the superficial and immediate, because we cannot try to remedy only the first symptom of a problem, without knowing its root cause and the most appropriate solution for it.

For example, if we return to the example of illness and vomiting, we could simply stay in bed with a container nearby; or if our car does not start, go to work by public transport. Indeed, both would be solutions, but only for the symptoms and not for the underlying causes of them.

Therefore, in order to analyze the problem or contingency that affects our organization, and thus obtain the relevant lessons, we must discover exactly what its cause is, and how to solve it. Moreover, for this, it is essential to apply a correct ACR.

Treating individual symptoms could give us the false confidence that we are solving a large number of problems. However, if the true root cause is not diagnosed, we will probably suffer them, over and over again.


Before applying an RCA, you must be clear about the following basic principles:

– Recognizing and treating symptoms alleviates problems, but only in the short term.

– It is necessary to concentrate on correcting and remedying its root causes, to solve them in a definitive way and try not to repeat themselves.

– The same problem could have multiple root causes.

– The most important thing is to determine how and why something happened, and not who was responsible.

– Be methodical to find the concrete cause-effect evidences, which support the respective root cause claims.

– Provide sufficient information to determine a corrective course of action.

– Take the necessary conclusions regarding how we can prevent a root cause in the future.

All these principles demonstrate that an accurate analysis of problems and root causes requires adopting a comprehensive and holistic approach. That is, along with discovering the root cause, we must strive to provide the necessary context and information, to take action, or make a decision.

In other words, you must always remember that all good analysis is one from which you can act.


There are various ways of applying an RCA, based on different theoretical conceptions. However, specialists agree that the most currently are as follows: “the 5 why”; the “change / event analysis”; and the “fishbone diagram”.

1. Approach of the “5 why?”

Also known as, the “annoying child approach”, this methodology implies that, before each symptom of the problem, you should ask the question “why?”, followed immediately by an additional, and deeper, question of the type: “Fine, but why?”

This scheme replicates, in essence, the behavior of an upset child who tries to understand the reason of an indication or instruction. Is based on the logic that his attitude is particularly effective for practicing root cause analysis.

Common sense suggests that around five “why?”, will allow you to recognize most root causes. However, as it is not an exact science, the final amount may vary depending on the situation.

For example, we are the administrators of a soccer team, and one of our players suffers a fracture of the tibia and fibula, due to a blow from an opponent during a match.

Our player has a problem: He cannot walk or play anymore

– First “why”: Why you cannot walk?

– First answer: Because my leg hurts a lot.

– Second why: Why does your leg hurt?

– Second answer: Because I have a serious injury.

– Third why: Why do you have such a serious injury in your leg?

– Third answer: Because a rival hit me hard and broke my bones.

– Fourth why: Why did he break your bones?

– Fourth answer: Because I was not wearing large shin guards.

– Fifth why: Why weren’t you wearing large shin guards?

– Fifth answer: Because we didn’t have enough shin guards in the locker room.

Then, as Archimedes would say: “Eureka!” After five questions, we managed to discover that the cause of this serious injury was probably the lack of available protectors. As a conclusion, in the future we could reduce the risk of these types of fractures by ensuring that each player has a pair of long shin guards available. (Of course, this equipment do not make us immune to fractures, so additional care will always be required).

This practical example shows that the methodology of “why” avoids assumptions, since each new question offers increasingly clear and concise answers. In addition, the ideal is that the last “why” leads us to discover which process failed, and what is the more relevant solution.

2. Analysis of changes / Analysis of events

Another method used to perform a correct RCA is analyze carefully the potential changes that lead to an event. This is especially useful when there are a large number of probable causes. In addition, instead of worrying about the specific time when something went wrong, we can look at a longer period to get historical context.

– First, we made a list of all potential causes that led to the event. They must consider every moment in which a change occurred, positive or negative.

– Then, we must classified each change or event according to the influence we had on it. We can categorize it as internal / external, provoked / unprovoked, or something similar.

– Next, we reviewed event by event, to decide if it was an unrelated, correlated, contributing factor or a probable root cause. This is where we do most of the deep analysis, and we can use other complementary techniques, such as the “5 why?”

– Finally, must observe how the root cause can be replicated or remedied. In order to establish an adequate preventive strategy.

3. Fishbone diagram

This method, also known as the “Ishikawa diagram”, allows to visually mapping the cause and effect of a problem, by following categorical paths, and branching out to the possible causes, until reaching the correct one.

Usually the problem is located in the middle of the diagram first (this corresponds to the backbone of the fish skeleton). Then, a brainstorm identify the several possible categories of causes; and arrange them in the different branches that arise from the main line (these correspond to the bones or “spines” of the fish skeleton).

The categories can be quite broad, and include elements such as “people” or “environment”, among others. After grouping them, we must divided them into smaller parts. For example, under “people” category you could identify possible root cause factors such as “leadership”, “staff” or “training”.

As we delve into potential causes and sub-causes, we can get closer to the sources of the problem. This method is useful to eliminate unrelated categories, and identify correlated factors, and possible root causes.

In order to apply successfully a fishbone diagram, we must always include the following common categories:

– Machine (equipment, technology)

– Method (process)

– Material (includes raw materials, consumables and information)

– People / mind (physical or knowledge work)

– Measurement (inspection)

– Mission (purpose, expectation)

– Management / money (leadership)

– Maintenance

– Product (or service)

– Price

– Promotion (marketing)

– Process (systems)

– People (staff)

– Physical evidence

– Performance

– Environment (place, environment)

– Suppliers

– Abilities


If you want to carry out a complete and successful analysis, then follow these recommendations:

Ask questions to clarify the information and get closer to the answers

The more you inquire and interrogate each potential cause, more likely you will find a root cause.

Do not stop until the details are behind

Only when you have already identified the root cause of the problem (and not just another symptom), ask more strategic questions such: Why are we sure, this is the root cause, rather than this? Or, How can we fix this, in order to root cause help us to prevent the problem from happening again?

Simplify strategies

Use simple questions like “why?”, “How?” and “what does this mean here?” This will optimize the search for paths, in order to understand the problem on better ways.

Always work as a team

Could be just your partner or a whole team. Any additional look will help you find solutions faster, and give you better bias control. Additionally, the comments of others will offer you additional insights, which will help you to challenge any assumptions.

Act methodically

Before applying a certain RCA technique or method, investigate whether it corresponds to the specific environment and needs of your company or business. If the analysis has already started, and you still have doubts, you can take notes or ask questions about the process itself.

Also, analyze the success stories

RCAs not only identify problems. They can also be effective in finding the root cause of a success, especially if it is an excessive or premature achievement. This type of analysis helps to prioritize resources, in order to protect key factors, and to translate success from one business area to another.

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About the author

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Francisco Gonzalez

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