Accelerate Your DFMEA with Sherlock!

© 2004 - 2007 © 2004 - 2010 9000 Virginia Manor Rd Ste 290, Beltsville MD 20705 | 301-474-0607 | www.dfrsolutions.com © 2004 – 2010

Accelerate Your DFMEA with Sherlock!

DfR Solutions Webinar

Cheryl Tulkoff

[email protected]

November 20, 2012

© 2004 - 2007 © 2004 - 2010 9000 Virginia Manor Rd Ste 290, Beltsville MD 20705 | 301-474-0607 | www.dfrsolutions.com

o Review of Design Failure Mode & Effects

Analysis (DFMEA) Concepts

o What Sherlock Is

o How Sherlock Can Help

o How Sherlock DFMEA Works

o Summary

o Questions

Agenda


Introduction


o DFMEA is just one of many tools in your tool box.

o It is not the only tool or best tool for every problem or every situation.

o It can be used across a wide range of fields and disciplines

o Not limited to “hardware”

o Manufacturing

o Software

o Business Processes

o Healthcare

o Service Industries

o Regulated industries – automotive, medical devices, NASA..

o Any place where you need to reduce risk and prevent failure!

What DFMEA is NOT… the only tool to use!


What DFMEA is….

o DFMEA

o A systematic group of

activities designed to:

o Recognize and evaluate

potential failures of systems,

products, or processes

o Identify the effects and

outcomes of the failures

o Identify actions that could

eliminate or mitigate the

failures

o Provide a historical written

record of the work performed


Why perform a DFMEA?

o Purpose of an DFMEA Study is to analyze:

o What might go wrong?

o How bad might the effect be?

o How might it be prevented, mitigated or detected at the earliest possible moment?

o With lowest cost, impact, safety risk….

o Develop a DFMEA process for use in future designs


FMEA in the News

Japan’s Fukushima Daiichi

nuclear plant

Industry watchers contend a

manufacturing error was likely the

culprit. "It means the assembly was

wrong, it means the wrong tools were

used, it means they were careless in

drilling the holes, and maybe the drill

was dull,"

Tear in Boeing Jet

A study has found that fatal

medication errors spiked by

10 percent in July, the month

that graduates fresh out of

medical school report to

residencies, in counties with

a high number of teaching

hospitals, but stayed the

same in areas without

teaching hospitals Medication Errors


o Japan Quake & Tsunami points out both strengths and limitations of FMEA o Key issues were detailed and identified

o The plants were built to withstand an earthquake of 7.0.

o There was a seawall around the facility in case of a tsunami.

o In an earthquake, the plants had a SCRAM procedure, which executed an emergency shutdown of the nuclear reactors.

o Electrical pumps were designed to pump cool water to the container to keep the rods submerged (the rods are hotter AFTER the shut down than during regular operation of the plant).

o There were back-up batteries for running the pumps in an emergency that were designed to last about an hour or so.

o There were diesel fuel pumps that were available to take over the pumping when the batteries ran out of juice.

o There are vents built into the system to release steam from the reactors if the pressure inside got too high

o But many were considered low probability and/or excessively expensive to consider or the risk was underestimated

FMEA in the News……

http://en.wikipedia.org/wiki/Scram


o Boeing engineers underestimated the risk of cracks in

the aluminum, they assumed it would be fine for

60,000 flights (pressure cycles) but have now reduced

the expected life to 30,000 with inspections

recommended every 500 flights after reaching

30,000….

o http://online.wsj.com/article/SB100014240527487038063

04576244782850491122.html

o FMEA: The Cure for Medical Errors

o http://www.medicalhealthcarefmea.com/guides/qp0803reili

ng.pdf

o http://asq.org/sixsigma/green/pdf/preventing_medication_

errors.pdf

FMEA in the News

http://online.wsj.com/article/SB10001424052748703806304576244782850491122.html



http://www.medicalhealthcarefmea.com/guides/qp0803reiling.pdf




o DFMEA is a widely used and powerful analysis & design review

technique.

o Extremely comprehensive element by element review of:

o What can go wrong

o What will happen

o How the situation can be improved

o For improving a design

o For each design component or element:

o List how failures can occur (Failure Mode, what can go

wrong, how the failure manifests itself)

o List what could happen (Failure Effect, consequences of the

mode).

o List how processes or the system itself can detect & prevent

the problem

o Generate Recommendations for Improvements.

DFMEA Basics - Failure Mode And Effect Analysis


o Failure: The loss of expected or intended function under stated conditions

o Failure mode: The way in which a failure is observed; generally describes the way the failure occurs.

o Failure effect: The immediate consequences of a failure on operation, function or functionality

o Failure cause: Defects in design, system, process, quality, or part application, the underlying cause of the failure or things which initiate a process which leads to failure.

o Severity: The consequences of a failure mode. Severity considers the worst case outcome of a failure as determined by the degree of injury, property damage, or harm that could ultimately occur.

Some Key DFMEA Terms


o Calculate a Risk Priority Number (RPN) for Each Line Item using

3 Criteria,

o Severity of the Failure Effect “S” (Scale of 1 (Low) - 10 (High)).

o Frequency of Failure Occurrence “O” (Scale of 1(Infrequent) -

10 (Frequent)).

o Detectability/Preventability/Warning “D” (Scale or 1(Very

Detectable) - 10 (Not Detectable)).

o RPN = S x O x D, range (1 (good) to 1000 High Risk).

o An unacceptable range is defined.

o Example: RPN’s > 150 are unacceptable and require a

corrective action redesign.

o Often a Pareto Ranking of the RPN is performed and used

to prioritize corrective action efforts.

DFMEA Basics - Failure Mode And Effect Analysis



o “Fill in the blanks” only.

o Don’t understand the scope and objective of FMEA

o Day dreaming

o Didn’t go through the self-challenge process of design control

o Couldn’t separate Failure Mode, Cause, Effect

o Mixed everything together. Argument for the sake of

argument.

Common DFMEA Mistakes and Traps


o Repeated itself

o Dog chases its own tail.

o Mitigation is not truly challenged

o Ranking criteria too loose

o Only identifying the problems but not the solutions. Or, couldn’t control it, even if there is a solution. Control plan not in place.

o Do once, then keep in file

o Leaving Document rather than Living Document

o Lack of consistency

Common DFMEA Mistakes and Traps


o So, how can Sherlock help?

DFMEA’s and Sherlock


o An automated design analysis tool to bring insight and

prediction earlier in product development process

Sherlock


Old Strategies…


The Solution

The Future

Will be

Modeled


o PCB Design

o Temp Cycling

o Vibration

o Shock

o Bending

o In Circuit Test

o DFMEA

o Thermal Derating

o Failure Rate

o etc.

Requirement: Solve Everyone’s Problem


o Demonstrated to avionics customer that transition to Pb-free

would have a detrimental impact to product performance

o Driven by severe use environment

Case Study C: Pb-Free Transition

SnPb Assembly SAC305 Assembly


o Automated to Save Time and Money

o Sherlock Automated Design Analysis™ Software automates most of the time consuming DFMEA process, potentially saving you and your organization up to thousands of hours every year.

o Standards Compliance:

o AIAG

o SAEJ1739

o Complies with ISO S26262

o Pre-populate Your DFMEA Spreadsheet

o Takes your standard design files

o Bill of materials, net lists, Gerber, etc.

o Automatically prepopulates DFMEA reports with reference designators, component technology (capacitor, resistor, etc.), and failure mode (open, short).

Sherlock DFMEA Module


o Sherlock is Fast and Smart

o Specializes in electronics design reliability

o Automatically performs a comprehensive review of pin location and net

o Automatically removes non-relevant shorting events, such as electrical shorts within the same circuit net.

o Occurs within a matter of seconds

o Not limited by the size of the design or the number of components.

o Complex Boards Simplified

o Unique nesting capability allows designers to more easily analyze complex boards.

o Nests DFMEA worksheets for ease of organization and visibility

o Allows designers to view the overall circuit as well as sub circuits and components.

Sherlock DFMEA Module – Tailored for Electronics


o So, how does Sherlock DFMEA work?

DFMEA’s and Sherlock


o Sherlock automatically imports Net List data for

ODB++ or Eagle CAD files.

o For other projects, users must supply a standard IPC-D-

356 formatted file containing the Net List data.

o Once the file has been added to the “Files” list for a

given circuit card, select the “Net List (IPC)” file type &

Sherlock will load the net list data found in the file.

o Net List data associated with a given circuit card can

be viewed by doubleclicking the “Inputs >> Net List”

entry in the project tree.

Importing Net List Data


Sherlock – Imported Net List


o Sherlock maintains DFMEA data as a hierarchical

collection of the following types of data:

o One or more Subcircuits per Circuit Card

o One or more Parts per Subcircuit

o One or more Failure Modes per Part

o For maximum usability, DFMEA data is displayed and

managed as a graphical data tree, allowing users to

easily expand, collapse, browse and edit the data.

Managing DFMEA Data


Updating DFMEA Data from a Parts List in Sherlock

o To view the DFMEA

data tree, simply

double-click the

“DFMEA” entry located

in the Circuit Card

“Inputs” folder of the

Project Tree. At that

point, the DFMEA

Viewer will appear as

a separate window.


Updating DFMEA Data from Parts List

o For each new circuit card,

the DFMEA Viewer will

initially contain no data

o Easily add default

DFMEA data entries by

right-clicking the circuit

card name in the

“Navigation” panel &

selecting the “Update

From Parts List” menu

option



o Dialog box appears allowing various processing options.

o Can create: o Default failures based on

part types

o Default “open” failures for all part pins

o Default “short” failures for all pairs of pins

o Select “Update From Parts List” button to create default DFMEA data entries for all parts in the Parts List.



o The Navigation panel is used to quickly find the data associated with any Subcircuit, Part or Failure Mode.

o As each entry is selected, data corresponding to that entry, and all higher-level entries, is displayed in the property panels located on the right-side of the main panel.


Manually Organizing DFMEA Data

o In addition to using the

“Subcircuit Name(s)”

property to organize

parts in the DFMEA

tree, it is easy to assign

one or more parts to a

specific subcircuit

After any DFMEA data changes are made, press the “Save Changes” button

to save all changes.

Press the “Reset Changes” to reset the DFMEA viewer to show the

previously saved data.


Adding Default Part Failures

o Use Sherlock to help create the failure modes

associated with each part

o Right click the entry just and select “Add Default

Failures” from the pop-up menu.


Manually Adding Failure Modes

o Create a Failure Mode

item manually by right-

clicking the part and

selecting “Add Failure

Mode”


Exporting DFMEA Data

o Flexible, user-customizable way to export all or part

of the DFMEA data to one or more spreadsheet files

using a collection of spreadsheet “templates”.

o To export DFMEA data, select the desired DFMEA

data and an appropriate template file


o 00-Backup-Template.xls

o 01-CCA-Summary-Template.xls

o 02-CCA-Details-Template.xls

o 03-Subcircuit-Summary-Template.xls

o 04-Subcircuit-Details-Template.xls

o 05-Part-Template.xls

o 06-Failure-Mode-Template.xls

Templates List


Importing DFMEA Data

o Same template used to export DFMEA data

from Sherlock can be used to import DFMEA

data from a spreadsheet into Sherlock

o Defaults to display last template used

o Press the “Load DFMEA Data” button to parse

the input file and begin the import process.


DFMEA Analysis Options

o DFMEA results are

generated by right-

clicking the Analysis >>

DFMEA entry in the

Sherlock project tree

for a given circuit card

& selecting the “Edit

Properties

o Save & Run

RPN values >/= or the “Error Cutoff Value”

are colored as errors (e.g., red)

RPN values greater >/= to the “Warning

Cutoff Value” are colored as warnings (e.g.,

yellow).

All other results are colored green.


DFMEA Results

o After the analysis has

completed, double-click

the “Analysis >>

DFMEA” entry in the

project tree to view the

DFMEA results

o Summary Results

o RPN Distribution Chart

o DFMEA Ratings Table

o Processing Issues


DFMEA Results

The “RPN Dist” tab shows a graphical distribution of the maximum RPN

values assigned to each part in the DFMEA data.


DFMEA Results

The “Table” tab shows a list of all parts defined in the DFMEA tree and the

maximum ratings assigned to the failure modes associated with those

parts.


DFMEA Layers

DFMEA module also generates graphical layers that display color-coded parts

based on the maximum RPN value assigned in the DFMEA data.


o Design Failure Mode and Effects Analysis (DFMEA) is

o Critical process in electronics design.

o Allows design engineers to identify and correct potential failure

modes early in the design process

o Improves overall product reliability

o Decreases cost

o Enhances customer satisfaction.

o But with increasingly complex electronics components, the time

required to complete a DFMEA can take weeks, adding to costs

and product delays!

o Let Sherlock accelerate your DFMEA efforts!

Sherlock DFMEA Module Summary


Questions & Discussion

Please feel free to contact me anytime for

questions!

[email protected]

www.dfrsolutions.com

mailto:[email protected]

Technology

Accelerate Your DFMEA with Sherlock!