Failure Mode Effects Analysis (FMEA)

Question 1

Failure Mode Effects Analysis (FMEA)

Answer 1

• Tool that helps us anticipate what might go wrong with a product or process.
• Also used to identify the possible causes and probabilities of failures.

Question 2

What’s a Failure Mode?

Answer 2

• A chance for a process to go wrong or an opportunity for a defect or variation to occur in a product
• Every process has potential weak spots. If we can recognize these in advance, we go a long way towards minimizing the damage caused

Question 3

When to Use FEMA

Answer 3

• Setting up a new process, before you start running it in a production environment
• Improving an existing process
• Changing an existing process - for example, modifying the type of material used
• Looking for existing quality control (QC) issues within a process

Question 4

DMAIC Phases Using FMEA

Answer 4

-Analyze and Improve phases

Analyze
-if your project is aimed specifically at finding issues in an existing process. This will help you figure out where things are already going wrong.

Improve

Question 4

DMAIC Phases Using FMEA

Answer 4

Analyze and Improve phases

Analyze
if your project is aimed specifically at finding issues in an existing process. This will help you figure out where things are already going wrong.

Improve
if your project has another aim - other process improvements, adding a new process, then you’ll use it to look for issues in your solution to the problem
Essentially double-checking yourself

Question 5

Types of FEMA

Answer 5

1. Design FMEA (DFMEA)
2. Process FMEA (PFMEA)
3. System/Functional FMEA (SFMEA/FFMEA)

Question 6

Design FEMA

Answer 6

• Focuses on a product or service
• Typically complete DFEMA before you put the new product or service into manufacture, or when you change the design of either.
• Use a DFMEA to minimize the effects of product failure on your customers
• By end of DFMEA, you should have strategies in place to correct all design issues identified

Question 7

Process FEMA

Answer 7

PFMEA looks at a process
Looks at the output from the process

Start a PFMEA at or after the feasibility study and before production begins.
Typically perform a PFMA after the DFMEA, as the latter is focused on design, and the PFMEA is focused on how you bring the design to life.

Question 8

System FMEA

Answer 8

AKA Functional FMEA (FFMEA)
Looks at the entire system on a high level
When performed, you look at things like the interrelationships between components and processes.
Can be useful because problems don’t just occur within processes or specific machines. They also occur between multiple processes or machines.

-Perform a SFMEA before the design phase where possible. This helps you to anticipate and work through issues that would otherwise affect your DMFEA.

Question 9

FMEA Inputs

Answer 9

• Inputs typically come from people who know the process, product, service or system very well.
• You’ll usually sit down and brainstorm potential failure points with these subject matter experts.

Question 10

FMEA Measurements

Answer 10

Three Key Scores:
1. Severity: How large the consequences of a failure mode will be. Some effects could be catastrophic (think a nuclear power plant meltdown). Others might be very mild (for example, a slight variation in product weight).

2. Occurrence: How likely the failure mode is to occur. Some failures might be very likely – for example, a laptop computer overheating outdoors in summer in Texas. Others might be very unlikely – for example, the nuclear power plant meltdown mentioned in the previous list item.
3. Detection: How capable the current processes are to detect the failure. If this failure mode occurs, will the responsible person know about it right away?

Scale of 1-10, these measurements are somewhat subjective. Try taking individual scores and calculating the mean for each.
*Some people use scale 1-5, but as long as you’re consistent it’s not too important

Question 11

FMEA Outputs

Answer 11

• Main output is a Risk Priority Number (RPN) for each failure mode
• RPN is an objective measure of the priority for fixing any one failure mode or failure mode effect.
• The bigger the RPN, the higher the priority.

RPN Formula:
RPN= Severity * Occurrence * Detection
If two RPNs are the same, review the severity ratings for each and go with the failure mode with the higher severity