Your Reliability Engineering Professional Development Site
“. . . not everything that can be counted counts” Albert Einstein
A key, but often missed, step in FMEA preparation is to identify and prioritize the functions that relate to the item being analyzed. These become candidate functions to be brought into the FMEA.
When creating a robust design, there is probably no more important consideration than identifying the correct parameters and associated values. A robust design is insensitive to anticipated variation and P-Diagram visually shows the relationship between what the system is designed to do, the anticipated noises the system will encounter and the correct parameters to achieve the desired outcome. P-Diagram can be an essential input to FMEA.
“Concern for man and his fate must always form the chief interest of all technical endeavors. Never forget this in the midst of your diagrams and equations.” Albert Einstein
Once you have identified the scope of the FMEA project, made the scope visible, it is time identify the FMEA team members. This article discusses the composition of the FMEA team, including why each member is needed, and the underlying reason for a cross-functional team.
“Alone we can do so little; together we can do so much.” Helen Keller
FMEA teams should agree to the ground rules that guide the analysis and the underlying assumptions that impact the entire FMEA. Failure to do so will add complexity and confusion to the resulting FMEA, and waste people’s time. Don’t miss this important step in FMEA preparation.
“Your assumptions are your windows on the world. Scrub them off every once in a while, or the light won’t come in.” Isaac Asimov
Before commencing with the FMEA meetings, it is essential to visibly show the nature and scope of the analysis. This article discusses different ways FMEA scope can be made visible, and why this is a necessary step.
“The soul cannot think without a picture” – Aristotle
Every journey begins with a statement of the goal or objective. Why would it be any different for FMEA? Yet, some FMEA teams do not clearly identifying the focus of the analysis. This sounds simple, and it is; but, it is very important. This article explains why.
“Begin with the end in mind” – Stephen Covey
This article culminates the first major milestone in the Inside FMEA series of articles: the “FMEA Fundamentals Series.” The next series is called: “FMEA Preparation Series.”
“Remember to celebrate milestones as you prepare for the road ahead.” Nelson Mandela
Can you take into account reliability or durability functions in an FMEA? How can this be done? A reader asks this question, and it is discussed and answered in this FMEA Q and A article.
“A prudent question is one-half of wisdom.”
Francis Bacon
In this week’s FMEA problems and solutions article, the intermediate problem challenges readers to prioritize a series of RPNs (with their corresponding S, O, and D). In the advanced problem, readers are asked to weigh in on a fictitious debate between advocates of traditional RPN, and advocates of criticality assessment, using only severity and occurrence.
If you haven’t yet read the article titled “Prioritizing risk for corrective actions in an FMEA – Know before you go!“, you can access it by clicking on the link.
Note from author:
Since this article was originally published, there are subsequent articles in the “Inside FMEA” series that further describe better approaches than RPN to risk prioritization. Here are links:
Is There a Better Way Than RPN?
Risk Prioritization in FMEA – a Summary
Is There a Better Way Than RPN?
Text of the original article:
One of the most important steps in FMEA procedure is prioritizing risk for corrective actions. As soon as Severity, Occurrence, and Detection ratings have been determined for each failure mode and associated cause, the next step in an FMEA is to prioritize the risk and identify which issues need corrective actions. This step has been misapplied more often than any other step in the FMEA process.
“The perfect is the enemy of the good.”
Voltaire
What if a production worker uses a different cleaning method for an assembly operation than was outlined in the operation work instructions, and the result is customer complaints and field issues. How could this be addressed in a Process FMEA? This question is discussed and answered in this FMEA Q and A article.
“I think that probably the most important thing about our education was that it taught us to question even those things we thought we knew.”
Thabo Mbeki
Can you find this common error in detection ranking in the intermediate problem in this article? In the advanced problem, the topic of an in-service detection scale will challenge the most experienced readers.
Failure modes and their causes can be detected in service, like tire pressure monitors on your vehicle. Is that what is assessed in the Detection column of the FMEA? This article discusses detection risk, including examples, and answers this question.
Ponder this question: Let’s say you are an OEM and assemble parts made by various suppliers. When performing your Process FMEA, do you consider special characteristics for components in your Process FMEA? This question is discussed and answered in this edition of FMEA Q and A.
“The key to wisdom is this – constant and frequent questioning, for by doubting we are led to question, by questioning we arrive at the truth.”
Peter Abelard
Assessing the occurrence ranking is one of the more challenging aspects of FMEAs. This article presents problems that relate to occurrence risk assessment, based on a fictitious case study, and highlights a common mistake.