The 3 Most Popular RCA Tools

Unfortunately when it comes to life and reliability. there isn't a crystal ball and unpredicted problems can occur in any team or process. However, problems are just symptoms of deeper issues. Fixing a problem quickly may be a convenient and immediate solution, but it doesn’t protect you from recurring mistakes or ongoing failures. That is why it is so important for teams to focus on finding the root cause of the problem and tackling it properly.

Odds are, you've already done a Google search and found the many options and preferred methods out there. To help narrow it down, we’ll focus on the three most commonly used tools during a Root Cause Analysis (RCA). From the most basic of tools, the 5 Whys, to a bit more detailed fishbone Diagram, and onto a more comprehensive and complex tool, the Cause Map.

5 Whys Process

The 5 Whys technique is one of the simplest, most effective tools for RCA in the Lean Management arsenal. Every team faces roadblocks in their daily work. However, using the 5 Whys will help you find the shallow root cause of any problem and protect the process from recurring mistakes and failures.

Origin

Developed by Japanese inventor and industrialist, Sakichi Toyoda, the 5 Whys method became an integral part of the Lean philosophy and is delivered as part of the induction into the Toyota Production System (TPS). Taiichi Ohno, considered to be the father of TPS, described the 5 Whys method as, “the basis of Toyota’s approach is to ask why five times whenever we find a problem… by repeating ‘Why?' five times, the nature of the problem, as well as its solution, becomes clear.” Extending well beyond Toyota, the tool is now used within Kaizen, lean manufacturing, and Six Sigma. 

5 Why Analysis in Action

A key factor for the successful implementation of the 5 Whys technique is to make an informed decision. To do so, the decision-making process must be based on an insightful understanding of what is truly happening on the work floor. In other words, the RCA process should include people with practical experience because logically they can give you the most valuable information regarding any problem that appears in their area of expertise.

When applying the 5 Whys technique, you want to find the essence of the problem and then fix it. However, the 5 Whys may show you that the source of the problem is quite unexpected. Often issues that are considered technical problems, turn out to be human and process problems. Therefore, finding and eliminating the root cause is crucial if you want to avoid iteration of failures.

From the example above, you can see that the root cause of the initial problem turned out to be something different from most expectations and that it is not a technical problem, but a process problem. This is a typical scenario because we often neglect to focus on the human factor and only focus on the product part of the problem which is why the 5 Whys analysis is so effective. Its purpose is to inspect a specific problem in depth until it shows you the real cause. Bear in mind that much like age, “5” is just a number. You can ask “Why” as many times as you need to complete the process and take appropriate actions but remember to stay focused.

Getting Started

The 5 Whys is a great tool to help you achieve continuous improvement at any level of your organization. When creating a 5 Whys, here are some basic steps to follow: 

Step 1: Form a Team

Try to assemble a team of people from different departments who are familiar with the process that is going to be investigated so you can gain unique points of view.

Step 2: Define the Problem

Discuss the problem with the team and make a clear problem statement to help define the scope of the issue you are going to investigate. Be as focused as possible to find an effective solution in the end.

Step 3: Ask Why

Designate one person to facilitate the whole process by asking questions and keeping the team focused. The facilitator should continue asking “Why” until the team can identify the root cause of the initial problem.

* At times, there could be more than one root cause. When this occurs, the 5 Whys analysis will display more like a matrix with different branches and can help detect and eliminate organizational issues that can have negative impacts on overall performance.

Step 4: Take Action

After the team detects the root cause(s), it is time to take corrective actions. All members of the team should be involved in a discussion to find and apply the best solution that will protect your process from recurring problems.

Summary

The 5 Whys is a simple and effective problem-solving tool with the primary goal of finding the exact reason that caused a given problem by asking a sequence of “Why” questions. Benefits of using the 5 Whys method include:

• Keeping your team focused on finding the root cause of any problem
• Encouraging each team member to share ideas for continuous improvement, rather than blaming others
• Giving your team the confidence to eliminate any problem and prevent the process from recurring failures

Fishbone/Ishikawa Diagram

The Fishbone diagram or Ishikawa diagram is a form of cause-and-effect but without the details. It helps to track down the reasons for imperfections, variations, defects, or failures.

The diagram looks just like a fish skeleton with the problem at its head and the causes for the problem feeding into the spine. Once all the underlying causes of the problem have been identified, you can start looking for solutions to ensure the problem doesn’t become a recurring one.

Origin

The idea of the fishbone diagram was revived by Japanese quality control expert, Professor Karou Ishikawa, at the Kawasaki shipyards in the 1960s. Ishikawa first used the Fishbone Diagram to explain to a group of engineers how a complex set of factors could be related to help understand a problem. However back in the 60s, the fishbone diagram wasn’t anything new. Even in the 1920s, it was seen as an important quality control tool and is still considered one of the seven basic quality tools today.

Fishbone Diagrams in Action

When it comes to quality and efficiency, variation equals imperfection and is your enemy. Whatever your business is, you don’t want to leave anything up to chance. From the moment your client contacts you, a predictable process aimed to complete customer satisfaction should be followed. Always remember... variation in the process, will mean variation in the product.

This is why the Fishbone Diagram is so effective; it helps you determine the variables that may enter the equation. Then allows you to make plans on how to deal with them in such a way that the quality of your final product is without compromise and significant variation.

Getting Started

The Fishbone Diagram is effective at identifying possible causes of a problem that might otherwise be overlooked because it directs the team to look at defined categories and think of alternative causes. When creating a Fishbone Diagram, follow these basic steps:

Step 1: Define the Problem

Start by naming the main problem or incident. This usually goes at the head of the “fish” on the right of your diagram.

Step 2: Decide Key Categories of Causes

Possible causes of variation may be numerous, but they will invariably fall into the following six categories: Personnel/People, Methodologies, Machinery, Materials, Measurements, and Environment. Once decided, use the key categories to feed into the “spine” of your fish skeleton drawing.

• Manufacturing industries most commonly use the 6 Ms (Material, Machine, Method, Manpower, Measurement, Mission/Mother Nature, Management and Money, Maintenance)
• Service industries most commonly use the 4 Ss (Supplies, Surroundings, Systems, Skills)

Step 3: Determine Actual Causes

Brainstorm all the possible causes of the problem by asking “Why does this happen?” List each of the causal factors as a line or fishbone from the appropriate category. Any sub-causes can be indicated by similar mini-fish bones attached to the line indicating the category under consideration.

Summary

Fishbone Diagrams are a great way to look for and prevent quality problems before they ever arise. If used to troubleshoot before there is trouble, you can overcome all or most of your teething troubles when introducing something new. Benefits of using a Fishbone Diagram include:

• Displays relationships clearly and logically for easy understanding and analysis
• Identifies the possible causes of a problem
• Reveals bottlenecks or areas of weakness in a business process
• Avoids reoccurring issues
• Ensures any corrective actions put into place will resolve the issue

Cause Map

People often think of cause-and-effect as a simple one-to-one relationship; an effect has a cause, but the reality is, every effect has causes. A Cause Map provides a visual explanation of why an incident or problem occurred by illustrating the relationship between a given outcome and all the factors that influence the outcome. It uses a systematic-thinking approach to RCA and focuses its analysis on causes supported by evidence. Cause Maps can also be referred to as a causal diagram and at times discussed in the same context as "Fishbone/Ishikawa Diagram" because of the way each line has relational aspects.

Fishbone Diagram vs Cause Map

Although the Cause Map and Fishbone are closely related, an obvious difference is that the fishbone diagram reads right to left. Kaoru Ishikawa created the Fishbone Diagram this way to follow his native Japanese language, which reads from right to left. The Cause Map method uses Ishikawa’s convention by asking Why questions in the direction we read, left to right, to build on the original lessons with the Fishbone but with some subtle, yet important distinctions:

• Cause Maps Tie Problems to an Organization’s Overall Goals
• Cause Maps Focus on Cause-and-Effect, not Categories
• Cause Maps Focus on Evidence-Based Causes
• Cause Maps Use a Systematic-Thinking Approach

Cause Maps in Action

Cause Maps can be used for several reasons, but are most commonly used to identify the causes and effects to get to a root cause, to sort out and relate some of the interactions among the factors affecting a specific process or effect, or to analyze existing problems so that corrective action can be taken. When you develop a Cause Map you are constructing a structured, visual display of a list of causes organized to show their relationship to a specific effect/symptom. Typically, the left or top box is the effect and the following box is the cause. As you build out the diagram the cause may become the effect of a new cause.

Getting Started

Cause Maps can be created from scratch, or by converting Five Whys or Fishbone Diagrams to provide a full line of sight. Here are some of the basic steps for constructing and analyzing a Cause Map:

Step 1: Define the Problem

Identify and clearly define the issue to be analyzed by its impact on overall goals. When the problem is defined by the impact on the goals, it allows for alignment across the team.

Step 2: Identify and Analyze the Causes

Break the problem down into a visual map to provide a thorough explanation revealing all the causes required to produce the problem. You can do this by asking a series of why questions to understand why the problem occurred.

Step 3: Find and Implement Solutions

Analysis helps you identify causes that warrant further investigation. Selecting the best solutions should prevent or mitigate any negative impact on the goals. Effective solutions should make a change in how people execute the work process.

Summary

A Cause Map is useful for identifying and organizing the known or possible causes of quality, or the lack of it, regarding equipment reliability, repairs, safety incidents, etc. Benefits of using a Cause Map include:

• Provides a structured approach to determining the root causes of a problem or quality characteristic using systematic thinking
• Follows an orderly, easy-to-read format to diagram cause-and-effect relationships
• Indicates possible causes of variation in a process
• Increases knowledge of the process by helping everyone learn more about the factors at work and how they relate
• Identifies areas where data should be collected for further study

Conclusion

Now that you have a better understanding of the 3 most popular RCA tools, the next step is determining which method or tool is right for you. While some organizations still follow an antiquated process with spreadsheets and paper, best-in-class organizations are using digital tools to more effectively and efficiently manage their RCA program. With software that will guide you through performing an RCA using all 3 tools, you can take the guesswork out of creating 5 Whys, Fishbone Diagrams, and Cause Maps and focus on ensuring every incident results in improvement. To learn more about the benefits of digital RCA software, check out our Investigation Optimizer™ tool.

Article Accreditation:

5 Why Trigger - kanbanize.com
Fishbone - tallyfy.com; cms.gov
Cause Map - reliabilityweb.com, .thinkreliability.com