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Root Cause Analysis: Different Techniques with One Goal

01 Aug 2023

Let’s say you have encountered the quality issues in certain processes or products. The next obvious step is to correct the same and keep things in order.  

Okay, you did the correction and things are back in order. The real concern arises when you face the same problem in the next production/development cycle. This indicates that the corrective measures you have taken earlier were temporary. And, you need some effective actions to prevent the problem occurrences time and again. 

The key to defining the effective action plan is identifying the root cause of the problem that only a thorough root cause analysis can help you with. RCA is often the most powerful method for resolving problems. 

What Exactly the Term Root Cause Analysis Means? 

A root cause analysis is a comprehensive process employed to determine the actual cause of a problem that occurs in a product, process, system, equipment, or supplier management. It helps you examine why is there a difference between the current state and desired state. 

Root cause analysis drives the momentum for continuous improvement in a quality management system due to its primary objective of correcting the actual cause of the problem. It helps to prevent the reoccurrences of similar problems in the future. It is more like a reactive approach to a problem that has already been occurred. However, with time and experience, you can use it for developing proactive strategies to attain quality. 

Root cause analysis doesn’t strictly run on a single defined methodology. There are different techniques used. Before heading to the tools and techniques, let’s have a quick look into the approaches for problem analysis conducted at different levels of organization based on; 

  • Safety  

Whereby the actual cause can be identified in accident analysis, more relevant for quality management in healthcare and automotive. 

  • Production  

Whereby the actual cause can be identified during quality control practices, more relevant in industrial and general manufacturing. 

  • Process  

Whereby the actual cause can be identified in the communication, more relevant in follow up and documentation process. 

  • Failures 

Whereby the actual cause can be identified during engineering and maintenance, more relevant in machine and equipment. 

  • Systems 

Whereby the actual cause can be identified with the fusion of any of the above-mentioned aspects. This is relevant in the risk assessment, change management system, and system analysis. 

How to Perform the Root Cause Analysis? 

The process of root cause analysis can be categorized into 7 phases that include: 

  1. Establishing the Problem Statement 
  2. Understanding the Problem 
  3. Mind-Mapping the Problem Cause 
  4. Gathering Relevant Data  
  5. Analyzing the Gathered Data
  6. Identifying the Root Cause
  7. Eliminating the Root Cause
  8. Implementing the Action Plan
  9. Checking the Solution Effectiveness

Different Methodologies used for Root Cause Analysis 

Getting to the actual cause of the problem requires you to follow the above-mentioned systemic approach. However, you can use different methodologies by customizing the workflows of your CAPA management system. Some of the most commonly used methodologies of root cause analysis are: 

Pareto Chart 

Based on the Pareto principle of 80/20 (20% of the efforts brings 80% of results), a Pareto chart is a bar diagram that in combination with line graph represents the frequency of problems with their significance. It is suitable for tackling the problems with multiple potential causes that you can arrange in the order of most important to the less important.  

The 5 Whys 

Next in the row comes – The 5 Whys. It is the most recommended methods of root cause analysis that doesn’t require you to collect data sets that reflect trends or behavior. This simple process involves asking at least 5 why question to a problem occurrence. However, you can ask more or less the number of whys until you get across the root cause(s). Isn’t it the simplest root cause analysis methodology? 

Let’s have an example here for better understanding –for an error that caused a part to be made that did not fit into the machine assembly: 

  • Why did the part not fit? – The part was too small. 
  • Why was the part too small? – The measurements were incorrect. 
  • Why were the measurements incorrect? – The mechanical engineer did not take down the dimensions correctly. 
  • Why didn’t he take down right dimensions? – Because his tools were not calibrated properly. 
  • Why his tools were not calibrated properly? – Because of his ignorance. 

The corrective action is to ensure that the engineer uses the calibrated tools to take down the right dimensions to enter in the system that is used for manufacturing the parts. A manual process will be long and time-consuming.  

But you can simplify it all with the help of the CAPA Management Software like Qualityze, designed to capture the early detection of recurring problems that may result in increased expenses, resources, and a possible customers’ complaints. This eventually affects product quality and market share. 

Fishbone Diagram (Ishikawa or Cause and Effect Method) 

No matter what you call it, the fishbone diagram is a quite useful technique for performing the root cause analysis. It basically categorizes the root cause based on People, Measurements, Methods, Materials, Environment, Machines. You may use the categorization industry-wise. For example, if you are in the manufacturing industry, you will find measurements, methods, materials, machines more useful.  

If you are wondering about the name FISHBONE, it is due to the categorization and sub-causes arrangement that looks exactly like a fishbone.

Scatter Diagram 

A scatter diagram is a graphical representation that shows the relationship between the two continuous variables with one on the x-axis and another on the y-axis that impact each other. However, this relationship can be further influenced by a third variable, let’s say Z. If your scatter diagram shows a straight line, it means the variables on the X and Y axis share a stronger relationship and will get affected by each other. Sometimes, the diagram often fails to capture the relationship of two variables because of insufficient coverage of data.  

Remember that the scatter diagram is used for the analysis of the numerical data. 

Failure Mode and Effects Analysis (FMEA) 

As the name itself specifies, this root cause analysis approach focuses on identifying different factors for failure in the system. This is generally used by the manufacturing industry. It can be broadly categorized into four steps: 

  1. All factors causing failure must be identified (exactly in the way any observed failure happens). 
  2. How many times the same cause of failure is identified?
  3. List of actions implemented to prevent the reoccurrence of the failure. 
  4. Check on the effectiveness and efficiency of the actions implemented.

FMEA methodology is implemented and updated at the time of launch of new products or processes in the system, most probably at the time of change especially at the time of new regulations or after receiving customer feedback. However, you can use change management software to streamline all the changes and their relevant processes. 

Fault Tree Analysis 

Yet another effective root cause analysis approach, FTA is based on the Boolean logic to find out the real cause(s) of an unfortunate problem occurrence. This can be used for risk and safety analysis too. The fault tree represents the nonconformance/undesired outcome on the top while listing all its potential causes down the line. The arrangement of fault and the potential cause is reflected in the shape of a tree; which is why it is named as Fault Tree Analysis. 

Current Reality Tree 

This RCA approach is used to analyze the entire system at once. It is commonly used in the scenario where you need to identify the root cause of many existing problems. The listing of CRT starts from the problems at the top, and then depicting their potential causes using IF and THEN analysis. As a consequence, you will be able to find out that actual cause, which might be leading to multiple problems. 

Hence, root cause analysis is a desired process for every organization, regardless of their industry type and size. They can go with the suitable tools to identify the root causes or potential cause to implement necessary action plans effectively and efficiently.  

You can make the entire root cause analysis even simpler with the help of a CAPA management software like Qualityze. Built on, it ensures flexibility, reliability, security, and scalability for your system and data.  

Stop by and contact our customer success team today to experience the Qualityze difference!  



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