What is root cause analysis?

Why the need for root cause analysis

Recurring problems are the bane of manufacturing. These problems result in an unwarranted amount of waste like machine malfunctions, redrawing a product, waste of resources, and time lost. Often, when technicians repair or address problems, organizations believe the main cause has been dealt with. In most cases, technicians only solve the symptoms, and the main problem occurs again.

When carried out correctly, a root cause analysis identifies the specific issues that lead to issues with systems. It pinpoints any non-conforming element and provides data to prevent it from happening again.

When organizations perform root cause analysis, they find out what happened, why, and how to prevent it from occurring again. Root cause analysis also outlines any improvements that technicians need to make to ensure the problem does not repeat. With the right use of root cause analysis, organizations can eliminate repeat problems.

Root cause analysis methods are not meant for manufacturing processes alone, although this is where it is primarily used. There are other numerous industries where it can be applied. Its varying methodologies are used in a structured manner to solve problems like:

• Quality control issues
• Healthcare incident analysis
• Accident analysis
• Failure analysis in engineering
• Management transitions and improvement activities
• Computers and software analysis
• Incorrect orders or shipments

Root cause analysis applies to many kinds of problems that any company may face on a day-to-day basis. Processes can be mapped and analyzed and any arising root cause can be found and fixed. The result is a happy client and a company that saves on operation costs.

How does root cause analysis work?

Root cause analysis is a step within organizational problem-solving exercises, and there are many root cause analysis tools that organizations can use. While some of these exercises can be undertaken by one individual on behalf of the organization, usually a cross-functional team achieves the best results. The chances of finding the actual root cause increase with a team in place.

Numerous problem-solving processes (such as 8D, the Six Sigma/DMAIC, or even Kaizen) make use of root cause analysis, which is a critical step in each of them.

Step 1: Putting together a team

A root cause analysis team needs to have a clear understanding and in-depth knowledge of the processes they examine since they will carry out any corrective measures. Team members need to represent every aspect of the issue: from quality assessment to process protocols. Each team member brings in unique knowledge and expertise.

Step 2: Start with the problem

Before attempting root cause analysis, a team must identify and define the problem:

• Who first found out about the problem?
• What happened exactly, in as much detail as possible?
• At what point in the process was this problem noticed?
• When was the problem found?
• How many times has it happened so far?
• Is there a pattern of occurrence?
• How was the issue detected?

With all of this information, the team may want to find out specific details to get a more well-rounded understanding of the problem. There may be a need at this point for short term containment or corrective measures. The team will need to review all collected information to define the possible problem based on the facts and data. Once they identify the problem, the process of root cause analysis begins.

Step 3: Use the correct tools for root cause analysis

Several tools are used in root cause analysis and are all designed differently:

Is / Is Not

This method may be used at any point in root cause analysis such as defining a problem’s scope or when planning a solution. In both cases, it helps the team focus and decide what should and should not be included. If the borders of the problem are not clearly defined, then the team may end up losing track and working on problems of little consequence. The is/is not process is where the team answers a range of questions such as:

• Who does this problem impact?
• Does the team in question have the authority needed to solve this problem?
• What is already known about the problem?
• Will the customer be impacted in any way?
• Can the team do something about this?

The team should ask these questions to come up with a clear definition and scope of the problem.

Ishikawa diagram

Also known as the fishbone diagram, this is a useful tool that arrives at the most likely causes of a problem. The name comes from the fact that the final image resembles a fish skeleton with the issue being outlined in a box at the end. The body of the diagram looks into the 6Ms: man, material, method, machine, measurement, and mother nature (the last being a reference to the environment).

The diagram is created right to left, with each major “bone” branching out into smaller ones with finer, related details attached. This is where the team brainstorms and comes up with as many possibilities. All ideas have to be placed in the right position in the diagram. Once all the possibilities are on the board, the team may be able to rate potential causes based on importance levels and the likelihood of that possibility failing. A hierarchy can be built this way. From within the hierarchy, the team can choose to go in-depth into specific causes to investigate more.

The 5 whys

Simply ask “why” until you move through all of the symptoms and arrive at the root cause. This is a tool that is frequently used in problem-solving activities. It can be used on its own or along with other analysis tools such as the cause-and-effect diagram.

Employing the five whys works the best when the people answering the questions are those who work on the issue in a hands-on manner. Repeating “why” helps drill right down to the root cause. A rule of thumb is that by the time the fifth “why” is asked, you have identified the root cause (any earlier and you may end up addressing a symptom). In the five whys format, you can also have three distinct ways to approach issues: why something occurred, why wasn’t it detected earlier, and why did systems fail for this to occur? When each area is explored, the chances of understanding the cause are increased.

Failure modes and effects analysis

This tool helps identify multiple reasons of failure that may exist within any system or process. In larger companies, if a serious issue is detected with the process or with the product, the entire team will have to work on reviewing all failure modes and effects specific to the problem. The team has to determine if the problem (or the impact of the failure) has been determined by the failure modes and effects analysis method, and how accurately this team evaluated risk. If the problem is not identified by this step, then the team will have to do the following:

• Determine that the current issue is a problem in design or process
• Determine the impact by outlining the severity of the issue
• List out all possible causes and the number of times they have occurred

If a process is under review, then the principles of failure modes and effects analysis must be applied to the process flow or diagram to find the root cause. The team can then identify an escape point in the process closest to where the root cause lies undetected. At this point, they will have to document any controls in place that are preventing the problem’s detection. They should make a list of additional possible actions that can prevent the issue’s recurrence and then execute a timely solution.

Step 3: Form an action plan

When the team has found the root cause with any tools, they will then have to come up with the right measures and corrective action. Additionally, the team will develop a plan for the implementation of these corrective measures, which are usually of two categories: short-term or long-term solutions.

Short-term solutions can be implemented in less than a week. Anything longer than a week is classified as a long-term measure.

Long-term measures, also called permanent measures, are usually complex and may need additional resources to implement accurately. They have to be implemented within a month, or they are given to the continuous improvement team for regular evaluation.

Within regular evaluation, corrective measures have to be defined and achievable by the designated team member. The action plan should be comprehensive and include due dates for each corrective measure. In some cases, corrective measures will need teamwork from multiple departments, in sequence or tandem. In such cases, action plans should create a tracker for appropriate progress assessment.

Step 4: Verification plan

A verification plan, or validation plan, is used to document the impact of corrective measures. This can be done by data recording or auditing tools used in root cause analysis. Teams can collect evidence to validate the efficacy of the measures. Additionally, the team must meet in a month to review the efficiency of their solutions and ensure that nothing else is needed.

Tips for performing effective root cause analysis

Keep asking questions: Ask questions that will clarify information more to bring you closer to better answers. The more every potential cause is interrogated, the more chances you have of finding the root cause and not a symptom. Once you have identified the root cause, then examine that further with questions like is there an alternative to this possibility or why is this the answer? Working simply, with questions like “why” and “how” and “what“ is the best way forward.

Use teamwork and fresh eyes: Root analysis requires teamwork and multiple minds. Bringing in a fresh set of eyes helps see things from a different perspective. Getting additional viewpoints can push team members to challenge their assumptions.

Plan for future analysis: Be prepared for future versions of root cause analysis. Write down notes and analyze the process you adopted. Look for techniques and methods that work with your specific requirements: business or environment. It is a good idea to perform root cause analysis for your successes too so you can repeat them in the future.

Root cause analysis is the ideal tool to understand where problems occur. It is typically used to diagnose problems but works just as well to analyze the cause of success. With this form of analysis, you can prioritize and nurture key factors as well as create templates that may replicate success.