October 15, 2023 | Mark Paradies

7 Secrets of Root Cause Analysis

What are the 7 Secrets of Root Cause Analysis?

This article is about practical root cause analysis tips that are secrets (if you judge secrets by how many people need to learn them). What are the 7 Secrets of root cause analysis? Read on to find out more.

Who’s Keeping the Secrets?

In over 30 years of human factors and root cause analysis study, I’ve learned a few things that everyone should know. I don’t keep these root cause “best practices” a secret, but you would think that I did. Why? Because I find so many “experts” and laypeople alike don’t understand what I see as obvious. So I thought, “Why not share the seven most important ‘secrets’ here?” Then, I could explain how the secrets are incorporated into the TapRooT® Root Cause Analysis System.

7 Secrets of Root Cause Analysis

Here are the seven secrets of root cause analysis:

1. Your root cause analysis is only as good as the info you collect.

2. You have to understand what happened before you can understand why it happened.

3. Your knowledge (or lack of it) can get in the way of a good root cause analysis.

4. Interviews are NOT about asking questions.

5. You can’t solve all human performance problems with discipline, training, and procedures.

6. Often, people can’t see effective corrective actions even if they can find the root causes.

7. All investigations do NOT need to be created equal (but some investigation steps can’t be skipped).

Read on for the details about each of the 7 Secrets…

Secret 1: Your root cause analysis is only as good as the info you collect. (garbage in = garbage out)

Most root cause systems operate as a “standalone” module. Information goes in, and an answer comes out. They don’t help investigators collect accurate information.

To make matters worse, some root cause tools actually start by developing a “hypothesis” and then collecting information to verify (or perhaps disprove) the hypothesis. Extensive research has proven that once an investigator becomes invested in a particular hypothesis, his/her brain automatically starts looking for “facts” to confirm the hypothesis and disregards “facts” that are counter to the hypothesis. The result? You find what you want to find. This is not a robust root cause analysis process.

7 Step Process

TapRooT® 7-Step Major Investigation Process
Copyright 2016 by System Improvements, Inc. Used by permission.

TapRooT® takes a completely different approach to how a root cause analysis process is used in an investigation. In the TapRooT® 7-Step Process (and in the 5-Step Process for simple investigations), the root cause analysis tools are used throughout the investigation to make every investigation phase, including information collection, more robust.

Step 1: Planning

The first tool from the TapRooT® Toolbox that helps an investigator collect info is the SnapCharT®. The investigator starts using this tool to organize the investigation and decide what evidence needs to be gathered and assigns a priority to secure evidence that might be lost.

Step 2: Determine What Happened

You may notice that in Step 2, there are four tools to help you collect information and determine the Incident’s sequence of events:

  1. SnapCharT® Diagram
  2. Equifactor® Troubleshooting Tables
  3. CHAP
  4. Change Analysis

When you attend the 5-Day TapRooT® Advanced Root Cause Analysis Team Leader Course, you will learn all these techniques plus advanced tools to conduct a special type of interview: the cognitive interview – that helps people provide better information to assist your investigation.

First Secret

That’s the first secret. Get accurate, complete, necessary information to understand the incident. If you try to analyze assumptions, you will be guessing at the root causes and fixing your guesses. That would be a “bad practice.”

Secret 2: You have to understand what happened before you can understand why it happened.

This secret seems obvious. Of course, you must understand what happened. But many investigators, and some root cause tools, start by asking “Why?” when they should be trying to understand “What happened?”

Starting by asking “Why” is jumping to conclusions. This can lead the investigator to find causes that they have jumped to because they didn’t first seek to understand.

How SnapCharT® Diagrams Help

In the TapRooT® System, the first tool an investigator uses is a SnapCharT® Diagram. Even for simple investigations, the SnapCharT® Diagram is the first tool used (see below).


A SnapCharT® Diagram is a visual depiction of the evidence. It focuses the investigator on “What happened?” Any assumptions (not verified facts) are easily identified by their dashed boxes. The investigator then continues to look for more evidence to verify the assumptions or show a different, but also possible, sequence of events and conditions.

A SnapCharT® Diagram is an evolving document. It changes as information is collected and Causal Factors are defined. An initial SnapCharT® Diagram for what was thought to be a simple incident is shown below…

As more information is collected and organized, the investigator realizes that the incident is more complex than the first thought. A simple sprained ankle brings out other issues that would have been missed if the investigator had just gone with their initial assumptions. See the SnapCharT® Diagram below to see the problems that were identified with a more thorough investigation.

SnapCharT® with Causal Factors

Jumping to conclusions or simply asking “Why” the employee stepped in the pothole probably would not include all the information collected in the SnapCharT® Diagram above.

Second Secret

You have to understand what happened before you can understand why the Incident happened, AND there are tools that can make the process of collecting information about what happened more efficient and effective.

Secret 3: Your knowledge (or lack of it) can get in the way of a good root cause analysis.

What? Do you think this is obvious? That’s OK. Many don’t recognize how this secret interferes with root cause analysis.

Let’s start with a popular root cause myth: Cause and Effect.

Many think they can use the theory of cause & effect to find root causes. They assume that an experienced investigator who has seen a “cause” produce an “effect” can use that knowledge to diagnose future problems by using his/her experience to deduce the complex causal links (cause & effect chain) of an accident. This theory is the basis for many root cause analysis tools (5-Whys, Cause-and-Effect Analysis, and FMEA).

An obvious problem with this theory is that inexperienced investigators don’t know many cause-and-effect relationships. They can’t find what they don’t know.

But many don’t understand that even experienced investigators may be led astray by the assumptions behind cause & effect analysis. How? Read on…

Investigator Trap

Experienced investigators are often trapped by the same cause-and-effect assumption that traps amateurs. How? First, even the most experienced investigators don’t know all the cause-and-effect relationships that could cause an accident. This is especially true of the causes of human error. Many “experts” have little or no training or understanding of the psychology behind human error.

To combat the lack of knowledge, they recommend putting together teams of investigators with the hope that someone on the team will see the right answer. Of course, this depends on team selection to counter the inherent weakness of the assumption behind cause and effect. Also, it assumes that the rest of the team will recognize the right answer when another team member suggests it. Good luck! More likely, the “strongest” member of the team will lead the team to arrive at the answers that he/she is experienced with.


Experienced investigators often fall into the “favorite-cause-itis” trap. They use their experience to guide the investigation. This leads them to find cause-and-effect relationships that they are familiar with. Why? Because that is what they look for. They search for familiar patterns and disregard counter-evidence. (The technical name for this phenomenon is “confirmation bias.”) The more experienced the investigator is … the more likely he/she is to fall into the trap.

Exposing this secret doesn’t make me popular with experienced guru investigators. They don’t want to admit that they have the same weakness as inexperienced investigators when it comes to cause and effect analysis. They try to explain that they don’t have preconceived ideas about the causes of any accident. But of course, this statement flies in the face of the basis of cause and effect analysis – that experienced investigators know the cause and effect relationships of accidents and can recognize them (see the pattern) during an investigation.

TapRooT® RCA Overcomes Favorite-Cause-Itis

How does TapRooT® Root Cause Analysis overcome problems with “investigator knowledge”? Two ways.

First, it keeps the investigation focused on “What happened?” while information is being collected. Because investigators don’t prematurely jump to finding causes, they are more likely to follow the evidence where it leads rather than following it where they want to go.

The main tool they use for collecting evidence is a SnapCharT® Diagram. They also use Change Analysis, Equifactor® Equipment Troubleshooting Tables, and CHAP. This combination of advanced tools produces superior information to analyze.

TapRooT® Root Cause Tree® Diagram

But the real magic behind TapRooT® Root Cause Analysis is the Root Cause Tree® Diagram. The Root Cause Tree® Diagram takes the knowledge of hundreds of experts and makes it available to every investigator. (For the impressive list of sources used to build the tree, see Chapter 2, Section 2.5 of TapRooT® Root Cause Analysis Implementation – Changing the Way the World Solves Problems.)

Book 2 - Implementation

This knowledge doesn’t have to be in the investigator’s head because it is built into the Root Cause Tree® Diagram and the Root Cause Tree® Dictionary. Applying these systematic methods helps TapRooT® Users keep from jumping to conclusions. And it provides a check to make sure that causes aren’t overlooked.

The organization of causation in the Root Cause Tree® Diagram not only came from many reliable, advanced, sources but also was reviewed, critiqued, and tested. Beyond that, there are over 30 years of feedback from the international base of TapRooT® Users and members of the TapRooT® Advisory Board. This makes the TapRooT® Root Cause System a unique, advanced process for finding the real root causes of problems.

Third Secret

You should not rely on just your knowledge when performing a root cause analysis. You need an expert system to help you overcome favorite-cause-itis and confirmation bias. You need an expert system to double-check your root cause knowledge, making sure you don’t overlook causes.

Secret 4: Interviews are NOT about asking questions.

“What?” you might say … “I’ve always been taught to ASK questions as an interviewer.” What about the “open-ended and close-ended questions” routine that is commonly taught in root cause training? And what about asking “Why?” five times? I thought I had to ask questions during an interview?

Don’t Ask Why

Let’s start with the popular 5-Why myth…

I won’t review all the problems with the 5-Why technique. I’ll just mention the one that most applies to interviewing. Consider this … what happens when you ask somebody a question like:

Why did you do that?

Does the person answer with lots of information or with justification?

The “Why” question turns off the “remembering” trail in the brain. Instead, the interviewee starts down the “justification” trail.

The purpose of an interview to collect information (not justification).

That’s the first reason we don’t just ask questions (like “Why”) during an interview.

Directed Questioning

Next, let’s look at the whole process of “questioning” during an interview.

If the purpose of an interview is to collect information, we should use a process that stimulates remembering.

Researchers Fisher and Geiselman determined that the biggest problem with police interviews of witnesses of a crime was that the police interrupted the interviewees’ memory process with questions. It didn’t matter if the questions being asked were open-ended or close-ended. Every time the interviewer interrupted the interviewee, his/her memory had to shift gears. She/he lost her/his train of thought and didn’t remember as much as she/he could. The interviewer didn’t get to important facts. (Facts were omitted when the interviewee was distracted by questions.)

Not only did interruptions for questions cause problems, but also, the questions being asked didn’t help stimulate remembering. Fisher and Geiselman came up with a new interviewing process called “cognitive interviewing” that helps the interviewer encourage the interviewee to remember much more and thus improve the amount of information collected.

Another problem that was noted in Fisher and Geiselman’s research was that interviewees often tried to provide the interviewer with the “most important” information. They filtered what they told the interviewer. The interviewee didn’t understand that some detail that they thought was “unimportant” was something that the interviewer really needed. Because the interviewer didn’t know the details, they couldn’t ask about it. Therefore, the information was lost.

Fourth Secret

The way you interview people is important. There are techniques you can use to improve the effectiveness and efficiency of your interviews.

The TapRooT® 5-Day Advanced Root Cause Analysis Team Leader Course includes cognitive interviewing combined with the TapRooT® SnapCharT® technique to improve interviews. This shifts the interviews from questioning to a listening process. The cognitive interviewing process encourages interviewees to share all the info they know by encouraging them to remember. Also, the interviewee is told to provide details, no matter how small or unimportant.

If you would like to learn more about evidence collection and interviewing, read…

Book 7

Or attend the 2-Day TapRooT® Effective Interviewing and Evidence Collection Techniques Course being held prior to the Global TapRooT® Summit. To register for the course, CLICK HERE.

Secret 5: You can’t solve all human performance problems with discipline, training, and procedures.

Did you know that there are ONLY three standard corrective actions?

Three Standard Corrective Actions

If you look at most industrial accident/incident investigations, you find these three standard corrective actions:

1. Discipline. This starts with the common corrective action: “Counsel the employee to be more careful when …”.

2. Training. This may be the most used (and misused) corrective action of all.

3. Procedures. If you don’t have one, write one. If you already have one, make it longer.

The misuse of these three standard corrective actions is the reason that so many accident investigations don’t really cause performance to improve. They don’t solve the real problems (the real root causes).

Corrective Action Helper® Guide

What do we need to get better results? First, better root cause analysis. Second, the development of better corrective actions based on the root causes of the problems. And third, corrective actions that provide the strongest safeguards against future errors.

TapRooT® provides the best root cause analysis and the Corrective Action Helper® Guide to help investigators develop better corrective actions.

corrective action

The guide is included in the 2-Day, 3-Day Virtual, Equifactor®, and 5-Day TapRooT® Courses and is built into the TapRooT® Software.

The 2-Day and 5-Day TapRooT® Classes also teach Safeguards Analysis to help investigators understand that all corrective actions are not created equal. Students learn that there is a hierarchy of potential corrective actions and that they should not just use the corrective actions that seem easiest to develop and implement. Rather, they should look for the strongest corrective actions that will ensure that a problem does not recur.

Fifth Secret

Thus, the fifth secret is that you need more than just the three standard corrective actions to create performance improvement. Your investigators need guidance from the Corrective Action Helper® Guide/Software Module and guidance from Safeguard Analysis and the hierarchy of Safeguards.

Secret 6: Often, people can’t see effective corrective actions even if they can find the root causes.

Why? Because they have performed the work the same way for so long that they can’t imagine another way to do it.

I didn’t initially believe this. I thought that once someone saw the root cause of a problem, the answer would be obvious. But students in a course finally convinced me that I was wrong.

Bad Corrective Actions Example

Back in 1994, a team of students in one of our courses analyzed the root causes of a fairly simple incident. One of the root causes was that the valves being operated were not labeled. So far, so good.

But here was their corrective action:

Tell operators to be more careful when operating valves without labels.

They just couldn’t see that valves could be labeled. It was beyond their experience.

Creation of the Corrective Action Helper® Guide

That was the day I decided that we needed to do something different to help people see different corrective action alternatives. This revelation eventually led to the development of the Corrective Action Helper® Guide and the Corrective Action Helper® Module of the TapRooT® Software.

corrective action

The Corrective Action Helper® Guide/ Module provides suggestions that can help investigators discover that there are other ways to solve problems beyond those of their experience. It does not guarantee that they will get the right answer, but it does prod them in the right direction. Also, the Corrective Action Helper® Guide can be used by management to review the investigation team’s findings to see if they explored all the alternatives.

Sixth Secret

The sixth secret is similar to the fifth. People need help developing corrective actions. The Corrective Action Helper® Guide/Module can provide that help! The latest edition of the Corrective Action Helper® Guide comes packaged as a set with the Using the Essential TapRooT® Techniques to Investigate Low-to-Medium Risk Incidents and the Using TapRooT® Root Cause Analysis for Major Investigations books. CLICK HERE to order your copy.

Secret 7: All investigations do NOT need to be created equal (but some investigation steps can’t be skipped).

I’ve seen people cringe when asked to perform a root cause analysis. They think this means a team of selected experts spending months locked up in a room. After all, didn’t the CSB take over three years and spend over $3 million investigating the BP Texas City explosion?

It’s true that some investigations may take too long and cost too much. But that doesn’t mean that every root cause analysis needs to take too long and cost too much.

Root cause analysis should be scaled to the size of the problem and the risk of future accidents with similar causes. Small risk = small investigation. Big risk? Then, spend more time and more investigative effort … dot each “i” & cross each “t.”

The hard part of responding appropriately is assessing the risk of future similar incidents before the investigation starts. For example, sometimes, an incident that seems quite simple can have complex causes that could, in different circumstances, cause a big accident.

That’s why when we revised the TapRooT® System in 2015/2016, we created two separate investigation processes, two separate books, and two separate courses to apply TapRooT® Root Cause Analysis to investigating seemingly minor incidents and major accidents.

Two Processes

The process above and to the left is for simple incidents. The process above and to the right is for major accidents. They both use the essential TapRooT® Techniques (used for every investigation). The process for major investigations also includes the optional TapRooT® Techniques.

One major difference between the processes is that the simple process allows the investigator to stop the investigation when collecting information if the learning seems to be of little value.

Two Books

Picture of TapRooT® Investigation Essentials AND Major Investigations Book Set

The two different books are pictured above.

Using the Essential TapRooT® Techniques to Investigate Low-to-Medium Risk Incidents explains the process and tools used for simple investigations.

Using TapRooT® Root Cause Analysis for Major Investigations explains the use of the process and tools used to investigate major accidents.

Book 4 - major accident

What if your incident is something in between? Start with either process and use the techniques that you need (learn both processes in a 5-Day TapRooT® Advanced Root Cause Analysis Team Leader Course).

Two Courses

The 2-Day TapRooT® Root Cause Analysis Training teaches the “TapRooT® Essentials” that are used for simple investigations.

The 5-Day TapRooT® Advanced Root Cause Analysis Team Leader Training teaches both processes (simple and major) and all the TapRooT® Techniques. Plus, participants get both of the books listed above.

Seventh Secret

And that’s probably the biggest secret of all. TapRooT® Root Cause Analysis can handle all of your investigations from simple to complex. TapRooT® RCA is totally flexible while still being robust.

Apply All Seven Secrets

Now that you know the seven secrets, apply them in your investigations. The easiest way to do this is to apply TapRooT® Root Cause Analysis as the company’s standard incident investigation and root cause analysis technology.

Attend one of our public TapRooT® Courses held around the world.

Or contact us for on-site training by calling 865-539-2139 or CLICKING HERE.

Webinar: 7 Secrets of Root Cause Analysis – By Alex Paradies

Here is a webinar about these 7 Secrets of Root Cause Analysis…

Root Cause Analysis Tips
Show Comments

2 Replies to “7 Secrets of Root Cause Analysis”

  • ian McArthur says:

    I think you’ve just summed up the entire Taproot process there Mark,(with some of its none too obvious pitfalls) Jolly well done!

  • Douglas Duane Williams says:

    Very informative and explained at a simple level. useful tools and information. Thank you.

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