Lecture 3 - FMEA

Question 1

What is FMEA/ FMECA?

Answer 1

A FMEA is a systemised group of activities intended to:
* recognise and evaluate the potential failure of a product/process and its effect,
* identify actions which could eliminate or reduce the chance of a potential failure occurring, and
* document the process.

Question 2

Why is the focus on function not event?

Answer 2

• The FMEA process focuses on what we want the equipment/ process to do.
• By identifying what functions need to be achieved, we can then identify situations when the equipment does not perform the required function, and focus attention on the related causes and effects.

Question 3

When to do a FMEA?

Answer 3

• New design/ process/ technology…. used to identify design changes and maintenance/ operational tactics
  AND
• During the life cycle …. used to modify maintenance and operational tactics, consider risks of modifications to existing design or process, use of existing design in a new application.
• FMEA can be applied to products, software AND processes

Question 4

What do you need to do a FMEA?

Answer 4

• An appropriate team including knowledge of the asset and its operating context
• A functional breakdown of the asset
• Knowledge of the failure modes
• Risk tables for assessing severity (consequence), frequency of occurrence (likelihood), and detection effectiveness
• Documentation system for capturing the outputs

Question 5

FMEA TABLE

Answer 5

REFER TO SLIDES, including risk matrix

Question 6

What is Risk and Risk Priority (RPN Number)?47

Answer 6

• The Standard “Analysis techniques for system reliability – Procedure for FMEA” AS IEC 60812-2018 describes
• A measure of potential Risk as R= S x P, and
• The risk priority number RPN = S x P x D or S x O x D
• S = non-dimensional number for severity/ consequence;
• P = non-dimensional number for probability of occurrence/
  likelihood;
• D = a number indicating the estimate of chance that of identifying and eliminating the failure (high number = less detectable);
• sometimes O is used instead of P and is the probability of occurrence written as a probability.