failure modes: creating and using the dfmea

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