Root Cause Analysis

Lean workplaces try to identify the root causes of problems such as defects so those problems can be resolved at the source. Resolving issues at the source ensures energy and time is being spent on the true root of the problem, which will in turn solve the array of associated problems. The process of seeking out causes is often called root cause analysis.

Root cause analysis can be used to solve many types of problems including quality issues with products, safety incidents, productivity, problems with equipment, and more.

When performing root cause analysis, people often use the 5 Whys. This means they ask why something occurred until they arrive at the root cause of the problem. Users should ask why as many times as necessary to get to the root of the problem; 5 isn’t a required number. Another example of a root cause analysis tool is the fishbone diagram. The diagram is shaped like a fish and is a visual representation of the 5 Whys strategy.

Root cause analysis is important because what might seem to be an obvious reason for a problem is typically just a surface reason caused by a larger issue. For example, when assessing why a worker experienced a hand injury, someone might assume it was because the worker didn’t take the time to put on the correct safety gloves. It would be easy to jump to conclusions in this situation and blame the worker, when in reality the root cause of the problem could be that the correct size gloves for the worker weren’t available. This would be a mistake on the company’s part for not stocking appropriate personal protective equipment. Or possibly the worker was wearing safety gloves, but the proper machine guards weren’t placed on the machine. By implementing machine guards or providing the correct PPE and not just using a quick fix, a workplace can avoid injuries in the future and other related issues.

Essential Steps Of Root Cause Analysis

Here are the essential steps of Root cause analysis:

  • Define the Problem

    The first step in figuring out why something went wrong is to understand the situation. A small group of people, maybe those who know the most about the problem, will look at the situation and identify the most specific issues. They'll try to analyze how this problem affects the people who use the product or service. They'll ask questions like: "What exactly is the problem?" and "How does it make things harder for our customers?"

  • Collect the Data

    Gathering important information about a problem or event is key. Document all the details and features of what happened, which will help answer questions such as: What led to this issue? When did this happen? Does it happen often? What effects did it have? 

  • Identify Potential Factors

    To determine what caused a problem or event, a team should follow these steps:

    • Create a timeline of events to understand the order in which things happened.
    • Ask "Why?" questions to come up with as many possible causes as possible.
    • Use a visual tool, like a causal graph, to represent the connections between different events and help track down the main cause.
  • Determine the Root Causes

    During this stage, identify as many possible causes as you can. The team conducting the analysis can ask multiple "Why?" questions, examining the factors using a Fishbone diagram or using a Pareto chart to focus on the main causes and significant contributing factors, and involving stakeholders and other relevant teams in this process is crucial. 

  • Prioritizing and Addressing Root Causes

    When we've figured out the root causes, we need to decide which one to handle first. We should think about how much impact each cause has - the bigger the impact, the more important it is to address first. We should also consider how many problems are connected to each root cause, and if there are many, they are likely to have a bigger impact and should be addressed sooner rather than later.

  • Recommend and Implement Solutions 

    After determining and prioritizing the causes, find solutions and put them into action, and a good way to start is to get everyone involved and brainstorm lots of different ideas. You can also interview as many people as possible to get their thoughts and opinions. Implementing the solution should involve everyone and should consider all recommendations. 

Why Is A Root Cause Analysis Important?

RCA helps you find the real cause of a problem and address it directly instead of just dealing with the symptoms. Identifying and addressing the main cause prevents the problem from happening again in the future, and you do not just fix the problem temporarily but actually stop it from coming back.

Root Cause Analysis Methods, Tools & Techniques

There are many ways to figure out the underlying reason behind a problem. These methods can help you identify the main cause of an issue and understand why it happened, here are some common ways to do that…

The Fishbone Diagram: This tool helps you sort out all the possible reasons behind a problem into different categories. When you know what's similar between the causes, you can figure out what's most important and find the main reason for the problem. To use this tool, you draw a diagram that looks like a fishbone and the head of the fish represents the major problem, and the primary groups of reasons are on the lines. Then, you add smaller reasons that connect to each of the main groups.

Fault Tree Analysis (FTA): This method uses a logical approach to determine the main cause by visualizing the problem at the top of a chart and creating branches to represent the various subsystems affected. With FTA, you can figure out the root cause of a problem by looking at how different parts of a system are related. It is especially useful for risk identification in a system.

The 5 Whys Analysis: This technique is used in Lean practices to identify the underlying cause of a problem by repeatedly asking "why" questions and narrowing down and uncovering the root cause of an event. Typically, it takes no more than five rounds of questioning to reach the root cause, and it is highly effective in understanding the relationship between different causes and bringing clarity to the sequence of events.


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