10 Root Cause Analysis Tools You Need to Know

Author: Rob De La EspriellaBD3, CEO and Founder, BlueDragon IPS


To effectively conduct RCAs and prevent recurrence of the causes, root cause analysis tools, techniques and methodologies have been developed over the past century.

These root cause analysis tools are often packaged (bundled together) in RCA Methodologies that have become well known.  For example, the Ford 8D or Toyota A3 methodologies.  And in 2015, the BlueDragon Integrated Problem-solving System was developed as the most modern RCA approach of all.

In this blog, we discuss 10 of the most popular and commonly used tools and techniques used in root cause analysis. We also provide a historical perspective of how long they have been in use.  At the end, we will discuss how to modernize the use of the best elements of these tools in the RCA process.

10 Popular Root Cause Analysis Tools and Techniques

The traditional approach to casual analysis is to create a “tool box” and train personnel on the individual use of these of root cause tools and techniques. The ambiguity of how these tools are used collectively to identify root causes, and the lack of an integrated approach, are a constant source of frustration.  Those are just two reasons why BlueDragon’s creator set out to modernize the entire approach to RCA, as discussed below.

1. Control charts (1920)

Control charts were developed by Walter A. Shewhart at Bell Laboratories in the 1920s. Shewhart introduced the concept of statistical process control (SPC) and created the control chart as a tool to identify variation in a process.

2. Barrier Analysis (1930s)

In 1931, H.W. Heinrich introduced the “Domino Theory” of accident causation, which laid the groundwork for understanding the relationship between hazards, barriers, and targets. Originally called “Hazards-Barriers-Target Analysis,” Barrier Analysis is a technique that focuses on identifying the barriers that protect the targets from the hazards.

In modern applications, we now refer to this root cause analysis tool as “Analysis of Defenses.” Our line of defenses include administrative requirements, physical barriers and cyber controls in place to prevent bad things from happening (i.e. they should prevent the events and programmatic failures).

3. The 5 Whys (1930s)

This questioning technique was developed by Sakichi Toyoda, the founder of Toyota Industries, in the 1930s. Toyoda used this iterative questioning method to drill down to the root cause of problems in his manufacturing process. The technique was later incorporated into the Toyota Production System (TPS) in the 1950s and became a key tool in their problem-solving approach.

However, the 5 Why technique is being used as a root cause analysis tool when in fact is it simply a Socratic questioning technique.  By itself, it is too simplistic to be used in modern day RCAs, as that was not its original intended use.  But the technique of asking “why” repeatedly is a basic building block of Cause & Effect Analysis. when working on people problems, we simply ignore the “5” as it may take many more questions to get to the deepest-seated causes.

4. The Fishbone Diagram (1940s)

Developed by Dr. Ishikawa, the Fishbone is a visualization tool used to brainstorm the potential causes of a problem.  This tool helps teams brainstorm and identify causes from different perspectives such as such as Man, Method, Machine.

The Fishbone diagram is not an effective RCA tool as it does not manage complex issues well.  However, the “bones” in the Fishbone correlate with our modern holistic approach of attacking a problem from different perspectives. For example, Human Behaviors, Programmatic Interfaces, Equipment Interfaces, Management Interfaces, and the Working Environment.

5. Failure Modes And Effects Analysis (1940s)

FMEA is a systematic approach to identifying possible failures modes in a process and assessing their potential impact.  It is often used as a preemptive root cause analysis tool.

FMEA was first developed by the U.S. military in the late 1940s to assess the reliability of military systems. In 1949, the U.S. Army published the “Procedures for Performing a Failure Mode, Effects and Criticality Analysis” (MIL-P-1629). This is considered the first formal description of the FMEA methodology. FMEA was later adopted by the aerospace industry in the 1960s and then spread to other industries, such as automotive and healthcare.

6. Pareto Charts (1940s)

In the 1940s, Joseph Juran recognized the work of the Mathematician Vilfredo Pareto (1848-1923) and recognized it’s potential. Since its inception, Pareto Analysis has been one of the most valuable root cause analysis tools for analyzing quantifiable data.

Based on the Pareto principle that 80% of problems come from 20% of causes, a Pareto chart is a specialized histogram used to visually chart the frequency of various elements and their cumulative percent to the overall total, allowing us to focus on the most significant contributors. The chart helps teams focus their efforts on addressing the most critical issues first.

7. Task/Change Analysis (1940s):

Task analysis, as applied to human factors and ergonomics, emerged in the 1940s during World War II.

In 1947, the U.S. Air Force published a technical report titled “A Method for Man-Machine Task Analysis” by Robert B. Miller, which is considered one of the earliest formal applications of task analysis. Task Analysis is typically performed prior to performing an evolution to minimize risks.

Change Analysis evaluates “what actually happened” against “what should have happened,” and is typically performed after an evolution that did not go as planned, to identify what caused the deviations from the original steps.  Task and Change analysis are very similar and have been a part of the root cause analysis toolbox for decades.

8. Event & Causal Factors Charts (1960s):

Focuses on investigating the timelines related to specific incidents or events to determine their root causes.

The Events and Causal Factors (E&CF) charting technique was developed by the National Transportation Safety Board (NTSB) in the 1960s as a tool for investigating and analyzing transportation accidents.

9. Fault Tree Analysis (1962):

Fault Tree Analysis was originally developed in 1962 at Bell Laboratories by H.A. Watson, under a U.S. Air Force Ballistics Systems Division contract to evaluate the Minuteman Intercontinental Ballistic Missile (ICBM) Launch Control System.

FTA is used for equipment failures to assess the reliability of a system by analyzing potential failure events and their interrelationships. By constructing fault trees, organizations can identify critical system failures and vulnerabilities and implement preventive measures.

10. Management Oversight Risk Tree (1970s):

MORT was developed by William G. Johnson at the U.S. Atomic Energy Commission (AEC), the predecessor of the Department of Energy (DOE), in the early 1970s.

Mr. Johnson published reports that introduced the MORT concept and detailed the use of MORT in accident investigations and safety program evaluations.

How These 10 Root Cause Analysis Tools are Used in BlueDragon IPS

The BlueDragon Integrated Problem-solving System integrates the best elements from these traditional tools. Using First Principles Thinking, BlueDragon’s creator created a framework where all of these tools and techniques (and many more) are used seamlessly under one visual chart. On the BlueDragon chart we incorporated the following elements that result in a highly efficient and accurate results.

PHASE 1 of BlueDragon IPS: Gather, Organize, Analyze Data and Evidence; Develop Lines of Inquiry Questions

  • Events and Causal Factors Chart: the timelines describing what happened are incorporated into the BlueDragon chart but with more granularity. Also, performance evidence and not just timelines can be used here.
  • Barrier Analysis: the “Line of Defenses” in place to ensure work is done safely and correctly: administrative requirements, physical barriers and cyber barriers (what should have happened).
  • With timelines/performance evidence and the line of Defenses, we seamlessly can perform:
    • Barrier Analysis
    • Task Analysis
    • Change Analysis
    • Comparative Timeline Analysis.
  • Data Analysis is conducted during Phase 1 of BlueDragon IPS.  This includes any and all data analysis tools that are applicable.
    • Control Charts
    • FMEA
    • Pareto Charts
    • Fault Tree Analysis
    • MORT
    • Any of the tools used in Lean Six Sigma
  • Lines of Inquiry Questions: Questions that are developed from facts and evidence, insights gained from data analysis, and without bias. They are focused on symptoms.

PHASE 2 of BlueDragon IPS: Identify the Root Causes and Contributing Factors

  • Causal Analysis is conducted during Phase 2 of BlueDragon IPS. This includes the best elements of cause and effect tools and techniques:
    • Lines of Inquiry Questions: The Questions form the starting points for our lines of inquiry for cause and effect analysis, and are most effective when focused on the symptoms of a problem.
    • The Fishbone diagram: We use the bones of the fishbone (we call them themes), to attack a problem from multiple perspectives to ensure we take a holistic approach.
    • The 5 Whys: Asking WHY is the basics behind cause and effect analysis. We call this Socratic questioning technique “Why Staircases” as the 5 is not useful when solving people problems.

PHASE 3 of BlueDragon IPS: Corrective Actions to Prevent Recurrence

  • During Phase 3 of BlueDragon IPS, issue owners are assigned to the root causes and contributing factors. In Phase 3 we offer strategies to dramatically improve our chances of preventing recurrence:
    • The Hierarchy of Hazard Controls: to help focus on actions that eliminate the problem, rather than administrative requirements and more PPE.
    • Lean Mistake Proofing: to focus on strategies that make it impossible to make a mistake.
    • Extent of Cause Reviews: to determine to what extent the root causes and contributing factors are impacting other programs, equipment and personnel.
    • Get Rid of Stupid Stuff (GROSS): to prevent us from adding more layers of administrative trivia to our programs and procedures.


Traditional root cause analysis methodologies have become antiquated.

The evolution of RCA tools and techniques over the past century has enhanced problem-solving processes across various industries. From the pioneering statistical controls of Shewhart’s control charts to Johnson’s Management Oversight Risk Tree, each tool and technique has contributed to our understanding and management of underlying problem causes. However, traditional RCA methodologies instantly became antiquated with the onset of the internet and big data in the 1980s.

BlueDragon’s modern approach integrates root cause analysis tools

The BlueDragon Integrated Problem-solving System is the first new-age universal problem-solving system of its kind. It offers a powerful and comprehensive approach to problem-solving, integrating the best elements of traditional tools and techniques that have been in use since the 1920s to 1970s.

BlueDragon IPS provides a structured framework for identifying and prioritizing the root causes of problems. The problem-solving system draws upon the strengths of traditional tools while addressing their limitations. For example, using the bones (themes) on the fishbone but replacing the diagram, which has a tendency to become unwieldy when dealing with complex issues.

Moreover, BlueDragon IPS incorporates cutting-edge scientific principles and models that make it much more accurate and efficient than any of the current RCA methodologies.  For example:

  • BlueDragon uses Lean to eliminate waste in the RCA process.
  • It incorporates tenants from Agile to make RCA more efficient.
  • It draws upon Weick and Sutcliffe’s research on the traits of High Reliability Organizations (HROs).  HROs emphasize the importance of mindfulness, preoccupation with failure, reluctance to simplify, sensitivity to operations, and commitment to resilience.
  • BlueDragon considers Edgar Schein’s work on organizational culture, recognizing the impact of shared values, beliefs, and assumptions on problem-solving efforts.
  • It incorporates elements of risk management and the hierarchy of hazard controls, to help organizations prioritize and implement effective solutions that minimize risks and improve overall performance.

Through this holistic approach, BlueDragon IPS equips organizations with a robust and adaptable problem-solving framework that leverages the best of both traditional and modern methods.


About the Author:

Rob De La EspriellaBD3, CEO and Founder, BlueDragon IPS

Deming Prize winning team member and pioneering Nuclear Quality Assurance expert Rob De La Espriella draws from four decades of experience in the commercial nuclear power sector and the nuclear weapons complex to offer deep insights into Root Cause Analysis and Total Quality Management. Rob is a leading expert in solving complex human-centric problems in our modern work environments, and has re-defined how organizations solve complex problems with the BlueDragon Integrated Problem-solving System (IPS), the first universal problem-solving system that can be applied to all regulated industries.  Rob is a former nuclear submarine officer, a decorated Resident Inspector with the US Nuclear Regulatory Commission, and a senior manager at commercial nuclear power plants. He was also on the Florida Power & Light team that won the Deming Prize from Japan.  Since 2007, he has been a Senior Policy Advisor for the Department of Energy and their contractors, helping solve some of their most complex issues.  Rob is a adjunct professor at Endicott College in Beverly, MA, and in 2023, he was accepted into the Forbes Business Council and is a Forbes contributor.

© 2024 DLE Technical Services, LLC. All rights reserved.

BlueDragon horizontal logo on a transparent background

Attention Retired Executives!

Are you a retired executive from a regulated industry looking to stay engaged through consulting work? We are seeking highly motivated partners to leverage their expertise and earn 10% commissions on new contract sales.

If you have executive experience in our target industries and a strong professional reputation to utilize, this is the perfect opportunity to supplement your income through flexible contracting work without needing to rebuild your client base from scratch. We provide the sales and marketing support, you provide the expertise – it’s a winning partnership!

Click here to set up a 30-minute meeting with us.

Open chat
Hello 👋
Can we help you?