Accendo Reliability

Your Reliability Engineering Professional Development Site

  • Home
  • About
    • Contributors
    • About Us
    • Colophon
    • Survey
  • Reliability.fm
  • Articles
    • CRE Preparation Notes
    • NoMTBF
    • on Leadership & Career
      • Advanced Engineering Culture
      • ASQR&R
      • Engineering Leadership
      • Managing in the 2000s
      • Product Development and Process Improvement
    • on Maintenance Reliability
      • Aasan Asset Management
      • AI & Predictive Maintenance
      • Asset Management in the Mining Industry
      • CMMS and Maintenance Management
      • CMMS and Reliability
      • Conscious Asset
      • EAM & CMMS
      • Everyday RCM
      • History of Maintenance Management
      • Life Cycle Asset Management
      • Maintenance and Reliability
      • Maintenance Management
      • Plant Maintenance
      • Process Plant Reliability Engineering
      • RCM Blitz®
      • ReliabilityXperience
      • Rob’s Reliability Project
      • The Intelligent Transformer Blog
      • The People Side of Maintenance
      • The Reliability Mindset
    • on Product Reliability
      • Accelerated Reliability
      • Achieving the Benefits of Reliability
      • Apex Ridge
      • Field Reliability Data Analysis
      • Metals Engineering and Product Reliability
      • Musings on Reliability and Maintenance Topics
      • Product Validation
      • Reliability by Design
      • Reliability Competence
      • Reliability Engineering Insights
      • Reliability in Emerging Technology
      • Reliability Knowledge
    • on Risk & Safety
      • CERM® Risk Insights
      • Equipment Risk and Reliability in Downhole Applications
      • Operational Risk Process Safety
    • on Systems Thinking
      • Communicating with FINESSE
      • The RCA
    • on Tools & Techniques
      • Big Data & Analytics
      • Experimental Design for NPD
      • Innovative Thinking in Reliability and Durability
      • Inside and Beyond HALT
      • Inside FMEA
      • Institute of Quality & Reliability
      • Integral Concepts
      • Learning from Failures
      • Progress in Field Reliability?
      • R for Engineering
      • Reliability Engineering Using Python
      • Reliability Reflections
      • Statistical Methods for Failure-Time Data
      • Testing 1 2 3
      • The Manufacturing Academy
  • eBooks
  • Resources
    • Accendo Authors
    • FMEA Resources
    • Glossary
    • Feed Forward Publications
    • Openings
    • Books
    • Webinar Sources
    • Podcasts
  • Courses
    • Your Courses
    • Live Courses
      • Introduction to Reliability Engineering & Accelerated Testings Course Landing Page
      • Advanced Accelerated Testing Course Landing Page
    • Integral Concepts Courses
      • Reliability Analysis Methods Course Landing Page
      • Applied Reliability Analysis Course Landing Page
      • Statistics, Hypothesis Testing, & Regression Modeling Course Landing Page
      • Measurement System Assessment Course Landing Page
      • SPC & Process Capability Course Landing Page
      • Design of Experiments Course Landing Page
    • The Manufacturing Academy Courses
      • An Introduction to Reliability Engineering
      • Reliability Engineering Statistics
      • An Introduction to Quality Engineering
      • Quality Engineering Statistics
      • FMEA in Practice
      • Process Capability Analysis course
      • Root Cause Analysis and the 8D Corrective Action Process course
      • Return on Investment online course
    • Industrial Metallurgist Courses
    • FMEA courses Powered by The Luminous Group
    • Foundations of RCM online course
    • Reliability Engineering for Heavy Industry
    • How to be an Online Student
    • Quondam Courses
  • Calendar
    • Call for Papers Listing
    • Upcoming Webinars
    • Webinar Calendar
  • Login
    • Member Home
  • Barringer Process Reliability Introduction Course Landing Page
  • Upcoming Live Events
You are here: Home / Articles / Is the 5-Ys a Valid RCA Tool for Significant Events?

by Robert (Bob) J. Latino Leave a Comment

Is the 5-Ys a Valid RCA Tool for Significant Events?

Is the 5-Ys a Valid RCA Tool for Significant Events?

I think that 5-year olds had a lock on 5Y’s well before it became a ‘named problem solving tool’. How many times have our kids at that age asked ‘Why’ about everything?

How many ‘Why’s’ do we answer before we say, ‘I don’t know, go ask your mother or father!’

Again (to me), the traditional 5-Y tool is technically incapable of expressing multiple paths of logic that occurred simultaneously. It treats failure like it always happens in a linear pattern (never multiple, simultaneous paths).

Like many other veteran analysts, I do not believe there is a magic number of ‘5’ levels deep for our analysis. Why not ‘3’ or ‘8’ levels?

5-Y’s also gives the impression there is only 1 root cause. Having been doing this for nearly 30 years, I have never been involved in an investigation that had only 1 root cause. I have never seen a professional investigation of a high visibility event in any industry with one root cause.

We drill down until we understand the flawed reasoning from well-intended decision makers (we call these Latent Root Causes or the flawed management/organizational systems).

I do NOT view 5-Y’s as a valid and capable RCA tool for higher severity/priority events that require more comprehensiveness and depth. As always, I am open to debate on this (and I am sure I will hear from opponents), but I will continue to ask for case studies where traditional 5-Y’s was used successfully on such high severity/priority events. Perhaps such a case will enlighten us ‘5-Y’ skeptics, as it being a valid RCA tool.

A big part of the problem with these types of discussions on the various forums is, there is no universally accepted and shared RCA dictionary of terms; we all define things in our own way. I think many of us are saying the same thing, but the lack of uniformity of terms makes it appear we are in conflict. We all have unity in purpose though!

Filed Under: Articles, on Maintenance Reliability, The RCA

About Robert (Bob) J. Latino

Robert Latino is currently a Principal at Prelical Solutions, LLC, along with his brother Ken Latino. Bob was a Founder and CEO of Reliability Center, Inc. (RCI), until it was acquired in 2019. RCI is a 50-year-old Reliability Consulting firm specializing in improving Equipment, Process and Human Reliability. Mr. Latino received his Bachelor’s degree in Business Administration and Management from Virginia Commonwealth University. For any questions, please contact Bob at blatino@prelical.com

« The Net Present Value Method: Measuring the True Value of an Investment
Why is Nobody Talking About This? »

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

logo for The RCA article series image of BobArticle by Robert (Bob) J. Latino
Principal at Prelical Solutions, LLC

in the The RCA article series

Join Accendo

Receive information and updates about articles and many other resources offered by Accendo Reliability by becoming a member.

It’s free and only takes a minute.

Join Today

Recent Posts

  • Gremlins today
  • The Power of Vision in Leadership and Organizational Success
  • 3 Types of MTBF Stories
  • ALT: An in Depth Description
  • Project Email Economics

© 2025 FMS Reliability · Privacy Policy · Terms of Service · Cookies Policy