Your Reliability Engineering Professional Development Site
I tend to write about all things Root Cause Analysis (RCA). I come from a background that engrained a holistic view of Reliability Engineering into me. This involved equipment, process and human Reliability. I write about the following types of RCA topics:
1. The Definition of ‘RCA’ and Why I Think the Current Term is Useless
2. When Should RCA’s be Conducted? Addressing the Application of RCA Proactively versus Reactively
3. What’s the Difference Between Root Cause Analysis and Shallow Cause Analysis? Why Do ‘RCA’ Efforts Fail
4. The Critical Task of Evidence Collection and Preservation to an Effective RCA
5. The Correlation Between Reliability/RCA and Safety, Does Such a Correlation Exist?
7. The Measurement of an RCA System’s Effectiveness
8. The Creation of an RCA Knowledge Base and its Sustained Growth to Store ‘Corporate Memory’ and Leverage Using AI
Lets start with a fresher on general Component Fatigue.
Let’s start off with some honesty…the term ‘RCA’ (Root Cause Analysis) is quite vague, misleading and easily misinterpreted by those who are not immersed in its use. It is a useless and counter-productive term because there is no universally accepted, standard definition. Therefore, any process/tool someone is using to solve a problem is likely to be labelled as ‘RCA’. It could be troubleshooting, brainstorming and/or some other more structured problem solving approaches such as 5-Whys, fishbone diagrams, causal factor trees and/or logic trees.
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Author’s Note: I want to reiterate that this Series about reading the basic fracture surfaces, is for novices who often come into contact with such failed components. This Series is about the basics (101), and is intended to give readers an appreciation for the value of such ‘broken’ parts to an effective investigation/RCA. While this information will be rudimentary to seasoned materials engineers/investigators, I know they will all appreciate heightening awareness to the need to retain such failed parts for formal analysis, versus throwing them away and just replacing the part. Throwing away failed parts is a recipe for a repeat failure. When one does not understand why the part failed in the first place, they can’t prevent it from failing again.
In this article we will focus on how to actually incorporate the evidence (failed parts) from a failure, into a disciplined Root Cause Analysis (RCA) process.
To those following this Series, I will apologize for the front-end redundancy. I am doing so for those that are NOT following the Series and will read these articles independent of each other. If you are following the series (Thank You!) and proceed past the front-end stuff and to the shaft pics below:-)
Abstract. In our last series highlighting the 4 primary Failure Modes (FM) of component failures (erosion, corrosion, fatigue and overload), we discussed how to read fractured surfaces. In this follow up series, we will take a look at tips on how to collect, preserve and examine such failed components.
I recently attended a conference where I listened to a presentation on Human Performance Improvement (HPI) by Dr. Todd Conklin and other speakers advocating Dr. Conklin’s ‘Learning Team’ approach. This was the first time I had heard Root Cause Analysis (RCA) referred to as ‘old school’ and obsolete. This got me to thinking, given I have been in the RCA business for decades, is what I do for a living…obsolete?
In our last series highlighting the 4 primary Failure Modes (FM) of component failures (erosion, corrosion, fatigue and overload), we discussed how to read fractured surfaces. In this follow up series, we will take a look at tips on how to collect, preserve and examine such failed components.
Author’s Note: I want to reiterate that this Series about reading the basic fracture surfaces, is for novices who often first come into contact with such failed components. This Series is about the basics (101), and is intended to give readers an appreciation for the value of such ‘broken’ parts to an effective investigation/RCA. While this information will be rudimentary to seasoned materials engineers, I know they will all appreciate heightening awareness to the need to retain such failed parts for analysis, versus throwing them away and just replacing the part. Throwing away failed parts is a recipe for a repeat failure, when one does not understand why the part failed in the first place.
Author’s Note: I want to reiterate that this Series about reading the basic fracture surfaces, is for novices who often come into contact with such failed components. This Series is about the basics (101), and is intended to give readers an appreciation for the value of such ‘broken’ parts to an effective investigation/RCA. While this information will be rudimentary to seasoned materials engineers, I know they will all appreciate heightening awareness to the need to retain such failed parts for analysis, versus throwing them away and just replacing the part. Throwing away failed parts is a recipe for a repeat failure, when one does not understand why the part failed in the first place.
This article is directed at those ‘first responders’ who arrive immediately at the failure scene. These are the people who have to ensure the area is safe, preserve the scene for investigators and contribute to a plan to expedite a quick, safe return to production norms.
Many do not understand how valuable failed parts are to the metallurgical/forensic investigators. Broken parts are to metallurgists’, like the murder weapon is to a forensic crime investigator.
Can you identify and name this fracture pattern?
How can you tell it is that fracture pattern?
Where are the origin(s) of the failure on the fractured surface?
How can you tell where the origin(s) are?
RCA Self-Assessment Tool. (linked version no longer available) The purpose of this tool is to allow individuals or groups to anonymously self-assess their current RCA system. How they wish to use the results is completely up to them!
All results are private and not retained anywhere. Therefore, if you wanted to keep your results, you would have to print them out and scan them back into your work station (or your past results are gone).
This failure occurred on a turbine driven boiler feedwater pump (TDBFP) at a fossil fuel power plant. The pump in question is an outboard boiler feed pump. Plant is operating normally when unexpectedly pump shuts down and causes a forced outage.
This is a failed shaft that came out of a pump in a paper mill. The pump was only in service for about a month before it failed unexpectedly.
From the top view above, identify the type of failure pattern that you see from the fractured surface(s). If you need more info to make your assessment, just ask.
Where does ‘failure’ come from? Why do some things not go as we planned? When bad things happen, at that time, it can be chaotic and appear very complex. Often, in hindsight (when the urgency has faded), we find that good people made bad decisions at that time. Most of the time such failures were not complicated and we find that most likely, anyone else put in the same position, would have made the same decision. So why do things not always go as planned?
Trick question, it’s neither!
When we hear people use the term ‘error’ it is normally associated with being the cause of some type of bad outcome. We hear it all the time with airline accidents where they conclude ‘pilot error’.
‘Error’ is neither the cause nor the undesirable outcome! Let’s see why.
Is the only type of error a ‘human error’? I struggled to think of an ‘error’ that is not a human error, so I asked if others could think of something else. I would like to thank Dr. Peter Elias who commented that errors can occur in biologic processes, such as RNA and DNA replication or messaging. He also cited non-human animals make errors all the time as well.