Karen Rayment, Case Forensics

Anchorage
Denver
Honolulu
Portland
Salt Lake City
San Francisco
Seattle
Spokane
www.case4n6.com
info@case4n6.com
assignment@case4n6.com
800.711.0704
SMALL UNMANNED SYSTEMS
BUSINESS EXPOSITION 2015
Karen Rayment, MSEE, MBA, P.E., CFEI, PMP
510-775-3394 Mobile
KRayment@CASEForensics.com
5 May 2015Categorization of Failures © Case Forensics 2014 – 2015, All Rights Reserved

1. Definitions- Categorize the Failure First, if
Possible: Legal Framework
2. FA Tips and Techniques: Put up Walls!
3. Business Considerations
a. Product Lifecycle to Help Clarify Remedies
b. Artifacts of Catastrophic Failures- Business
and Human Factors Losses
5 May 2015 2
Categorization of Failures © Case Forensics 2014 – 2015, All Rights Reserved

5 May 2015 3

◊ “The biggest problem in communication is
the illusion that it has taken place.”
- George Bernard Shaw
5 May 2015 4

1. Design Defect: Is a product inherently
dangerous, due to the design
specifications, for its intended purpose?
2. Manufacturing Defect: Were sub-
standard materials or processes used in
producing the unit in question, but design
is according to specifications?
3. Foreseeable Product Abuse: What would
a “reasonable person” do within the
intended use environment?
5 May 2015 6

5 May 2015 7

◊ Engineers MUST set aside emotional
language, such as customer reports
◊ Engineers MUST make a distinction
between a failure and its effects
◊ Engineers should always follow the
standard Scientific Method process flow
NOTE: With a working hypothesis, additional questions will
fall out- do one iteration of Scientific Method per
question!!!
5 May 2015 9

5 May 2015 10
◊ When products fail, people get panicky
◊ When people get panicky and don’t
understand something, they tend to
exaggerate the effects of failure
◊ CASE STUDY EXAMPLE 1 - Customer
comment was, “You almost burned my
house down, and my family almost died!”

5 May 2015 11Consumer Product Field Failures © Case Forensics 2014 – All Rights Reserved
◊ The wall power supply had experienced
overheating, and had a short between
power and ground traces, which caused a
SELF-EXTINGUISHING, SHORT DURATION,
LOCALIZED FAULT
◊ NOT ENOUGH AVAILABLE ENERGY TO
START A FIRE!
◊ Energy Considerations Include: Available
Mechanical & Electrical Energy, and Time

5 May 2015 12
◊ CASE STUDY RESULTS: The wall power
supply experienced a FAST, SELF-
EXTINGUISHING, LOCALIZED FAILURE

5 May 2015 13
◊ We can’t both replicate root cause, and
study field failure effects during the same
iteration of an experiment – lose patterns
◊ It is much easier to form a hypothesis
about root cause based upon observations
of effects, and then replicate effects and
backtrack to prove a hypothesis
◊ It is rare when a lab-created fault will
EXACTLY replicate a field failure – don’t
waste your time and effort

5 May 2015 14

From Legal Definitions - Categorize the Failure
First, if Possible: Most Likely a Manufacturing
Defect – Why?
◊ Product Lifecycle in the Market – Product has
been in Field Use for 3.5 Years, and CPU
Design is Older than the Product
◊ FA Tips and Techniques: Put up the Wall!
Hypothesis: Intermittent Fault in CPU is
Likely Due to Assembly Issue, not Bad CPU’s
5 May 2015 15

5 May 2015 16

May 5, 2015 17
◊ Case Study Results: Glue on printed
circuit board was contaminated by water

May 5, 2015 18
Step 1: Photograph area of interest, where
there is potential ionic contamination

May 5, 2015 19
Step 2: Use a scanning electron microscope
(SEM) to identify sample of interest

May 5, 2015 20
Step 3: Use energy dispersive x-ray
spectroscopy (EDS) to plot the elements
Green arrows on the
plot show the presence
of salt - sodium chloride
(NaCl) which indicates
fresh water was present
in or near the glue

From Legal Definitions - Categorized the Failure
Legally: Most Likely a Manufacturing Defect –
THIS WAS PROVEN
◊ Product Lifecycle in the Market – Product has
been in Field Use for 3.5 Years, and CPU was
Found to be Working Properly
◊ Outcome: Contaminated glue caused
bridging between power and data lines - CPU
was operating normally, but assembly defect
caused intermittent data clocking errors
5 May 2015 21

5 May 2015 22

245 May 2015

1. Introduction: Not well-known across a
wide variety of field conditions
2. Growth: May have several revisions in
the field, may have deviated from
regulatory compliance bill of materials
3. Maturity: Most likely lifecycle stage for
Manufacturing Defects
4. Decline: The least amount of Engineering
is dedicated, but more component issues
5 May 2015 25

265 May 2015
◊ Case Study: Test engineer for semiconductor
company sent email to another engineer that
was part of Discovery, “I don’t know why we
bother to test and grade these processors- we
know we are going to just sell them all anyway.”

275 May 2015
◊ Moral declined when the failures were
mentioned by brand name in the news.
◊ Then the team became emotional - attention to
detail declined, causing more sub-standard
products to slip through the QA final checks,
then more returns from customers.
◊ Downward spiral, company’s revenue plunged
for 2 years due to one bad batch of
approximately 50,000 units that were sold
without internal communication that they may
be sub-standard. People quit.

285 May 2015
“The San Jose, California - based company's
fourth-quarter loss was $22.7 million,
or $0.18 per share,
compared to net profit of $27.2 million
or $0.16 per share last year.”

The Small Unmanned
Systems Business
Exposition 2015

Karen Rayment, Case Forensics

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (19)

Similaire à Karen Rayment, Case Forensics

Similaire à Karen Rayment, Case Forensics (20)

Plus de sUAS News

Plus de sUAS News (20)

Dernier

Dernier (20)

Karen Rayment, Case Forensics