Root Cause Analysis Through Six Sigma

Root Cause Analysis Through Six Sigma

Root cause analysis (Acronym: RCA) can be defined as a problem-solving method that is used to identify the root causes of faults or problems.

A factor is considered a root cause if removal thereof from the problem-fault-sequence prevents the final undesirable event from recurring. Short-term actions are not profitable for the organization; thus, RCA help to eliminate the issues permanently. It is a collection of tools and processes we can use to determine the most important causes for an issue we are trying to resolve. This is an important function as one of the top 5 reasons for project failures is poor root causation / no root cause identified. If we can identify the root cause to an issue, we have a good chance of solving it.

Root cause analysis helps organizations to find solutions for all the types of problems that occur repeatedly when left unchecked in their natural form and state. Six Sigma root cause analysis tool helps organizations to find the most appropriate solutions. Root cause analysis is a collection of tools and processes we can use to determine the most important causes for an issue we are trying to resolve. This is an important function as one of the top 5 reasons for project failures is poor root causation / no root cause identified. If we can identify the root cause to an issue, we have a good chance of solving it.

Root Cause Analysis process involves data collection, analysis, root cause identification, initiating corrective actions, and implementation. It is performed to determine what happened, why the issue has happened, and what action to implement to reduce or eliminate it. Root cause analysis is used to identify issues in the process, analyze customer complaints, reasons for high rework, machine downtime, etc. In addition that it helps in identifying target opportunities improvement.

Six sigma champions determine the appropriate tool to implement root cause analysis

Five Whys is one of the most common ways used by six sigma champions to implement root cause analysis. The five whys is a basic root cause analysis technique to solve a problem, we need to identify the root cause and then eliminating it. The five why method is simply asking the question “Why” enough times until to past all the symptoms of a problem and down to the root cause.

Fishbone diagram is yet another method used by the six sigma champions to implement the root cause analysis A Cause and Effect Diagram in used in this approach. In other words, it is a visual representation to find out the cause(s) of a specific problem.

Yet another method of root cause analysis is brainstorming. It is a method for generating a large number of creative ideas in a short period of time. Brainstorming is full of energy, moves rapidly, and is synergistic, creating a large list of ideas which may eventually be convert it to a smaller list of priority items later in the project.


Defining, describing, and measuring the problems

The first step involves the determination and measurement of the problem. In this step, all the various aspects are considered such as when exactly does the problem occur, where exactly it occurs, what damage potential does it have, why exactly does the business need to solve the problem and how will the business will get benefited by solving the problem. This basically involves defining the problem and describing it in clear and comprehensive language. This gets accompanied by collecting the data and creating a timeline to visualize the sequence of events that occurred.

This is done by comparing the voice of the customer that represents customer expectations and the voice of the process that represents what customers are currently receiving. This approach helps the organization to devise effective solutions that are in line with customer needs and requirements.


Detecting the problem and coming up with effective and efficient solutions

After identifying the problem, the next step involves detecting the root causes and also understanding their connection with each other. This is done by collecting the data related to the problem and then using the root cause analysis tool for finding the main reasons behind the problem. This also includes differentiating the causal factors or symptoms and the root cause of the problem. It is also accompanied by prioritizing the root cause that needs to be addressed first, which has a high impact on the process

This step also involves finding the most well-suited solutions that along with solving the problem also ensure that the similar problem does not occur in the future again. Generally, multiple solutions are reached and they are put through advanced simulation tests to check their applicability. From among these, the best solution is selected and applied.


Implementation and administration

In this step, the organization needs to implement the solution and put in place the control systems that will help in verifying the success or failure of the implemented solutions. It is only after the implemented an solution passes the control tests, the organization can claim success for its problem-solving initiatives. Problems are a basic part of any organization. They can be present at any level or facet, and no tool or technique can ever claim to eliminate the occurrences of new problems. Six Sigma root cause analysis is preferred because it at least ensures that existing problems do not reoccur and are resolved in the most appropriate manner. This also involves monitoring the progress and communicating it with relevant stakeholders

 

 Benefits of Root Cause Analysis

1.      Root cause analysis helps to define the problem and identify the root cause(s) of the problem.

2.      It helps to identify improvement opportunities in the organization.

3.      It provides confidence to the customers that organizations are valuing the feedback and analyzing the root causes of the issues.

4.      Root cause analysis helps to implement mistake-proofing solutions I

5.      Root cause analysis helps to implement preventive actions in the organization.


The Root Cause Analysis Process

In order to move forward with RCA process, let’s take a quick look at who should be involved when you perform root cause analysis on any of the issues that you’ve identified in your production process.


Forming RCA teams – Who needs to be involved?

Anyone can contribute to the root cause analysis process and benefit from its tools and principles. So, the answer is simple: everyone. When it comes to the formation of a project team though, there are some general guidelines to keep in mind.

Most teams using root cause analysis to solve problems are small, only having 2-5 members. That said, depending on the problem and situational complexity, team size can vary. On rare occasions, they can even grow very large, spanning multiple departments with 30-60 members.

These teams are by nature and need, cross-functional. Typically, they will contain some variation of the following.

Subject matter experts (SME): SMEs provide specialized knowledge of the problem type. Or, they have experience working directly in the process being studied. For example, if we found that the format of the start of shift meetings that are run by the Operations Manager was not effective and we formed an RCA team to get to the bottom of why the Operations Manager would be a good candidate to consider as SME.

Manufacturing Engineering (ME): ME’S have a broad knowledge of the plant and deep expertise on its processes and equipment.

Quality Engineer or Process Improvement Specialist: Provide specialized expertise in quality and process improvement.

Manager or Supervisor of Process: This is crucial so that the team contains the authority to implement the proposed solution. Now that we know who should be involved in the process, we can look at which method to use and how.

Let’s start by looking at the six steps to perform root cause analysis.

Define the event

Find causes

Finding the root cause

Find solutions

Take action

Verify solution effectiveness


Define the event: Step 1 transforms the “big hairy problem” known at project initiation, into an accurate and impartial description of the event. It includes everything from forming the team, which we discussed in the previous section, to making a plan for the project. Though the most critical purpose of the step is to clarify what the problem is and define its scope.

It is critical to the success of the process that the team shares a common understanding of the problem. So, take your time at this step to make sure the groundwork is complete and correct.


Find causes: Step two, as you may guess from its name, focuses on finding potential causes of the event in question. Your goal should be to uncover as many causal reasons as possible. This pushes you to dig into the issues which will help you develop a deeper understanding of the problem. In this step, all voices should be welcomed and encouraged through exercises such as brainstorming, process mapping, and Fishbone Diagrams. Creativity and free-thinking will serve the team well and deserve encouragement almost to the point of a mandate.  The goal is to cast a net wide enough around the problem scope so that identification and consideration of all possible causes are achievable.


Finding the root cause: In step three, we have arrived at the reason why we began: to uncover the root cause that lies at the heart of the problem. Several tools can help us reach our goal. Below is a list of the most common tools that manufacturers use. While covering each of the tools is outside our scope, you can learn more in our article on Five Whys.

Common tools Five Whys, Histogram Fault Tree, Scatter Chart, Cause & Event, Tree Pareto Analysis.


Find solutions: Now it is time to turn our minds to the process of attempting to design a possible solution or solutions. Brainstorming is a very effective method for identifying potential solutions in a team environment. As you work through this step, we encourage you to involve as many people as possible. Anyone with a possible solution or who will face change from the implementation of a solution should be welcome.

Common tools: Interviewing, Brainstorming, Benchmarking, Flow Chart, Why Not Process.


Take action: The intent of step five is to implement the proposed solution that the team has created. Further, the team must take steps to ensure the sustainability of the change. Using an Impact Effort Matrix or Force Field Analysis may be helpful tools for this step.

The main ingredient for success at this step is tenacity and patience to see the project through to completion. There can be a tendency of project team members to bring the project to a conclusion. This is because the team will be approximately 4-8 weeks into the process at minimum at this point. Therefore, the team must be willing to avoid prematurely concluding that the problem was solved.

Finally, we need to ensure the changes and improvement stick. To this end, we recommend involving anyone who will be affected by a change now.


Assess solution effectiveness: In this step, we measure and assess the effectiveness of our implemented solution. This requires us to turn a critical and analytical eye on the solution to confirm that it has worked. If it has, then congratulations, the project’s conclusion has arrived. And it is time to look at the next issue that needs your attention.


Conclusion: We introduced the process to perform root cause analysis in much detail. This was accomplished by walking through six steps. This step-by-step look at the process and tools would have given you the base level knowledge necessary so that you can begin utilizing root cause analysis in your plant today. However, it must be said that there are indeed whole books dedicated to the subject of root cause analysis, many of which contributed to the basics presented in this article. If you are interested in further study, the following titles are a great place to start.

RCA through Six Sigma is an important component of continuous improvement in Six Sigma methodologies. Participants taking up this RCA through the Six Sigma course will learn about the tools such as the Cause and Effect Diagram (CED), 5 Whys, Current Reality Tree (CRT), and 8 Disciplines (8D) in order to determine and analyze the root cause. RCA through Six Sigma allows companies to identify the number of problems occurring each year and the possibility of their recurrence. It helps to determine whether the problems have known or unknown causes and classifies them accordingly. The RCA through Six Sigma course is designed for individuals, teams, and organizations that desire to institutionalize an operating system for structured problem-solving.

SHARE AT

0 Comments

Leave a Reply