To understand what a Root Cause Analysis (RCA) is, we must start from the fact that a root cause is a factor that causes a non-conformance and must be deleted through process improvement. The root cause is the central issue and the highest-level cause that sets in motion the entire cause-and-effect reaction that ultimately leads to the problem.

Situaciones que requieren análisis de raíz

Understanding this, the Root Cause Analysis (Real Cause Analysis or RCA) describes a wide range of approaches, tools, and techniques used to uncover the causes of any issues. RCA approaches may be geared towards identifying true root causes, some are general problem-solving techniques, and others offer support for the core activity of root cause analysis. Some examples of common situations where root cause analysis can help solve problems:

  • Manufacturing: A computer parts manufacturer identified that its products were failing in no time because of a design flaw in one of the microchips. After performing an RCA, a new chip was developed getting rid of the flaw.
  • Safety: After a patient suffered an unfortunate fall while inside a hospital facility, RCA found that they were not wearing non-slip socks. This led to policy changes including non-slip socks to ensure that all patients have this new additional safety measure.
  • Software development: Following complaints from customers about software that unexpectedly failed during use, an RCA was carried out, making it clear that there were design errors that caused the failures. The company applied new testing processes before launching any products, improving customer satisfaction.
  • Construction: The RCA performed for the delay in the completion of a project revealed that critical components had been delivered late, which led to the definition of stricter procurement processes to ensure timely delivery.
  • Commerce: In one retail store, shelves were found to be frequently empty. Performing an RCA found out that the store’s ordering process was inadequate, leading to order delays. A decision was made for the store to implement a new ordering process to avoid delays and keep the shelves fully stocked.
  • Food: A restaurant was experiencing frequent food safety issues. RCA found that employees were not trained in food safety procedures. The restaurant implemented additional training and supervision to ensure compliance with food safety regulations and prevent future issues.

The most common approaches to root cause analysis include 5W, herringbone diagrams, fault tree analysis (FTA), root cause mapping, and Pareto analysis. Later we will look at each of these approaches:

What is Root Analysis?

According to Techopedia, root cause analysis (RCA) is a problem-solving method used to identify the exact cause of a problem or event. The root cause is the actual cause of a specific problem or set of problems. Eliminating the cause prevents the final undesirable effect from occurring. This definition makes it clear that RCA is a reactive method, as opposed to preventive, since it will be applied only after a problem has occurred to look for its cause and prevent it from happening again.

The importance of RCA to address the underlying causes lies in the fact that it is an analysis based on processes and procedures, which help guide the problem analyst or decision maker to discover and understand the real causes of the problems and, therefore, reach a practical solution that prevents the recurrence of said problem.

Root Analysis Objectives and Benefits

RCA aims to identify the original source of a problem to prevent it from happening again. By addressing the root cause, it is also possible to implement appropriate preventive actions and measures. Even when the RCA approach is based on a reaction (the cause is analyzed from a problem that has already arisen), there are important benefits:

  • Cause Discovery and More Immediate Reaction: RCA allows you to intervene quickly to fix a problem and prevent it from causing widespread damage. The decision-making process should also be improved and be more timely.
  • Understanding for Effective Solutions: RCA details why a problem took place and helps understand the steps involved in the issue. The more details you get about the issue, the easier it is to understand and communicate why the issue took place and work as a team to develop solutions.
  • Applying Learning to Prevent Future Problems: By performing an RCA and taking the necessary steps to prevent problems from reoccurring, it is also possible to develop a mindset focused on finding problems more proactively.

Essential Principles of Root Analysis

To implement an RCA, its essential principles must be considered to ensure the quality of the analysis and, most importantly, to generate trust and acceptance of the analyst by stakeholders (suppliers, customers, business partners, patients, etc.) to undertake specific actions to get rid of and prevent problems. The principles underlying RCA are the following:

  • Focus on correcting causes, not just symptoms: The main focus is to correct and remedy root causes rather than just symptoms.
  • Importance of treating short-term symptoms: It avoids ignoring the importance of treating the symptoms of a problem to achieve short-term relief.
  • Recognition of the possibility of multiple causes: For the same problem, take into account that there could be multiple root causes.
  • Focus on “how” and “why”, not on “who”: Focus on how and why a problem happened, not on looking for liability.
  • Methodicity and search for specific evidence: To carry out an RCA you must be methodical and find specific evidence of cause and effect to support root cause claims.

It is also recommended to provide enough information to define a corrective course of action and look for how this information also contributes to the prevention of a future problem.

Finally, a comprehensive and contextualized approach is always recommended, considering that interdependent systems may be involved in a problem.

How to Perform an Effective Root Analysis: Techniques and Methods

To perform an RCA, there are four essential steps:

  1. Identify the issue/event: It is crucial to identify the issue or event at hand and engage all relevant stakeholders to clearly understand the scope and its impact.
  2. Collect data: It includes reviewing documentation, interviewing those involved in the situation, observing processes, and analyzing available information in order to develop a comprehensive view of the problem or event.
  3. Identifying root cause(s): Here several tools, such as the 5W methodology, herringbone diagrams, change analysis, and Pareto analysis, are used to analyze the data collected before devising solutions that address each identified factor. This could include process changes/upgrades, staff training or the introduction of new technologies.
  4. Developing and implementing solutions: Monitoring the effectiveness of the strategies chosen over time, being able to adjust them when necessary in the event that similar problems arise again later.
  5. Some techniques and models to implement an RCA are:

    • The 5W?

      It is the first and most popular RCA technique. This method involves asking “why” five times until the underlying cause of a problem is revealed. Detailed answers are found to the questions that arise. The answers become increasingly clear and concise. The last “why” should lead to the failed process. Example: If a manufacturing company has many defaults in its products, then by using a 5W analysis, it could be determined that no budget has been allocated because management did not.

    • Analysis of changes/analysis of events

      Consists of analyzing the changes that lead to an event for a longer period of time and a historical context is obtained. This method is recommended when working with several potential causes. This means:

      • Making a list of all the potential causes that led to an event and for each time a change took place.
      • Each change or event is classified according to its influence or impact (internal or external, caused or unprovoked).
      • Each event is reviewed and it is decided if it was an unrelated, correlated, contributing or probable root cause factor. Here you may use other techniques such as the 5W?
      • It is observed how the root cause can be replicated or remedied.
    • Fishbone Diagram (Ishikawa)

      These can identify root causes by breaking them down into categories or sub-causes. For example, in cases where customer satisfaction in restaurants is low due to service quality, food quality, environment, location, etc. are taken into account. These sub-branches are subsequently used to analyze the main reason for customer dissatisfaction. Example:

      As it can be seen, the diagram encourages brainstorming by following branching paths, which resemble the skeleton of a fish, until the possible causes are seen and it is visually clear how the solution would alter the scenario. To build the Ishikawa Diagram, the fundamental problem is placed at the head. After posing the fundamental problem, the spines of the fish are traced. The spine will be the link between the cause categories and the root problem. The common categories for this diagram are:

      • People involved in the process.
      • Method or how the work was designed.
      • Machines and equipment used in the process.
      • Materials and raw materials used.
      • Environment or causal factors.

      In the spines, attached to the spine, the categories or groups of cause are included. More spines (subcauses) can also be attached to the upper level spines, and so on. This causes the cause-effect relationship to be visualized.

    • Another method is the Pareto analysis

      Which is a technique that can help select the best solution for a problem when there are many potential solutions, especially when available resources are limited. Pareto analysis is derived from the 80/20 rule, which states that 80% of the results of an event are the product of 20% of contributions. This technique allows users to set aside a number of input factors that are likely to make the greatest impact on the effect or outcome. So, if the result is positive, individuals or companies decide to continue with the factors. On the other hand, users remove those factors from their action plan if the effect appears to be negative.

    Tips for Effective Root Analysis

    To implement an RCA, the first step is to determine a single problem to be discussed and evaluated. From there, follow these steps for an effective RCA:

    • Establish problem statement: By asking key questions, such as what is wrong, what are the symptoms?
    • Understand the problem: Relying on flowcharts, spider diagrams or a performance matrix, working as a team and accepting diverse perspectives.
    • Draw a mental map of the cause of the problem: To organize ideas or analysis.
    • Collect data on the problem: Relying on checklists, sampling, etc.
    • Analyze data: Using histograms, Pareto charts, scatter plots, or affinity diagrams.
    • Identify the root cause: Through a cause and effect diagram (such as herringbone diagrams), the five whys or event analysis.
    • Define deadlines and solve the root cause.
    • Implement a solution.

    Planning for future root cause analyses is recommended, keeping processes in mind, constantly taking notes and identifying whether a given technique or method works best for the needs of the organization and specific business environments.

    It is also recommended to do a root analysis in successful cases. RCA is a valuable tool to also find the cause of a successful result, the surpassing of initially set objectives or the early delivery of a product and later be able to replicate the formula for success. So RCA also helps to proactively prioritize and protect key factors.

    As a last step, it is recommended to monitor the solution, to detect if the solution has worked or if adjustments need to be made.


    Without a doubt, RCA is a valuable tool to identify the original source of a problem that can be critical for the organization and react quickly and effectively, as well as preventing the same problem from arising again. Beyond a reactive approach, RCA can help organizations implement preventive actions and measures, and can even map success (root analysis in success stories) to be able to replicate in the future the same key factors that have led to customer satisfaction, the achievement of adequate quality levels or the timely delivery of a product.

    Something also very important is that RCA allows to improve communication within the organization, detailing why a problem arose and what steps to take to solve it objectively. The more details you have of the context, the higher the possibility to engage the right people with clear courses of action, with informed and well-informed decisions.

    Of course, there are several root cause analysis tools to evaluate data, each evaluates the information with a different perspective. Also, to understand a problem, you have to accept different points of view and work as a team to achieve the benefits of RCA.