failure modes: creating and using the dfmea
TRANSCRIPT
Failure Modes: Creating
and Using the DFMEA
November 11, 2013
Learning Objectives
At the end of this session, you will be
able to:
1. Categorize potential failures for a design
2. Identify different test strategies
3. Describe different types of risk
Getting in teams
Get in a group of about 5
o About 5 is 3,4,5,6,7 at 8 split into two
Introduce yourselves
DFMEA :
Design for
Robustness
Pick one project from your
group for this section
DFMEA Steps
1. Review the design
2. Brainstorm potential failure modes
3. List potential effects of failure
4. List potential causes for each failure
5. Rank failures a) Severity
b) Occurrence
c) Detection
d) RPN = Severity X Occurrence X Detection
6. Develop action plan
7. Implement fixes
8. Revisit potential failure risks
In a group, identify one project
to use as an example for this
exercise
Describe the project so the whole group understands it
Brainstorm Failures
What could go wrong?
What could break?
Are there systems your design relies
upon?
o e.g. myEPICS authenticates through
Purdue’s career accounts
Are there things that could fail over
time?
Brainstorm a list of potential
failures and their causes for
one project
Rate failures
Rating
(1 to 10)
Severity How severe are the
consequences to
the failure
Occurrence
How often are the
failures likely to
occur?
Detection How easily are the
failures detected?
DFMEA Calculations
Scores for Severity, Occurrence and
Detection
o 1 to 10
o 1 = Low
o 10 = High
Risk Priority Number (RPN)
o RPN =Severity X Occurrence X Detection
DFMEA Matrix Failure mode Effect of
Failure
Cause of
failure Severity Occurrence Detection Rating
Take 5 potential failure
scenarios and rate them
Example
http://en.wikipedia.org/wiki/Failure_mode_and_effects_analysis,
accessed 22 Aug. 2011
Example Chart
Identify the failure scenario that
should be addressed first
Develop an action plan to
address the failure scenario
Continue the process
Implement the plan to eliminate the
failure scenario
Revisit other potential failure risks
o Prioritize
o Eliminate failure scenarios
Continue until risks are below
determined thresholds
o Show to the design reviews for
confirmation
Testing
Testing
o Kinds of tests
• User testing
• Proof of concept or technology – will it work
• Use testing
Correct conditions
Testing
What kind of tests are you doing in your
teams?
Other sources of risk?
What are other sources of risk to your
project?
Questions/Discussion