Applied Reliability Symposium – June 13-15, 2012, New Orleans, LA

Ops A La Carte’s Mike Silverman will be giving a presentation on "DFROI – Calculating ROI When Implementing a Design for Reliability Program".

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Competitive advantage is driven by cost reduction.  However, cost reduction is a by-product of the efforts to improve quality and reduce time of availability.

Reducing manufacturing changeover time (setup reduction -SMED) accomplishes this.  It provides the benefits of quality and time reduction while developing flexibility to respond to customer changes,

How well are you doing this?  What kind of insight and advantage are you giving your customers?  Understand what are the tasks to do this.

Contact the author for more direction in this area!

Mike Gozzo

An adaption of the Functional Safety standards IEC 61508 and IEC 26262 by the European Union brought a new life into slowly fading activity of reliability prediction. Both reliability prediction and reliability demonstration are now key parts of many product development programs, however despite phonetic similarity those two have little in common as well as the result they generate. 

While reliability prediction is an analytical activity often based on mathematical combination of reliabilities of parts or components comprising the system; reliability demonstration is based on product testing and is statistically driven by the test sample size.  Therefore the obtained results could drastically differ.  For example, a predicted system failure rate of 30 FIT (30 failures per billion (109) hours) would corresponds to a 10 year reliability of 99.87% (assuming 12 hours per day operation).  In order to demonstrate this kind of reliability with 50% confidence (50% confidence is considered low in most industries) one would need to successfully test 533 parts (based on binomial distribution) to the equivalent of 10 year field life.  Needless to say that this kind of test sample is prohibitive in most industries.  For example in the automotive electronics the test sample size of 23 is quite common, which roughly corresponds to 97% reliability with 50% confidence. 

The natural question is: how do you reconcile the numbers obtained from reliability prediction with the numbers you can support as part of reliability demonstration?

The answer is: I don’t believe that you can.

You can make an argument that reliability demonstration produces the lower estimate values.  Additionally the test is often addresses higher percentile severity users, thus the demonstrated reliability for the whole product population will likely be higher.  However, in most of the cases the gap will remain too wide to close.  This is something, which reliability engineers, design teams, and most importantly customers need to be aware of and be able to deal with as part of the product development reality.

What does the audience think? We’d love to hear your opinions on this.

Andre Kleyner

SMTA Conference on Soldering and ReliabilityMay 15-18, 2012, Toronto

Ops A La Carte’s Peter Arrowsmith will be giving a presentation at this conference on "Improving Product Reliability Using Accelerated Stress Testing".

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MD&M East

April 22, 2012 | Leave a Comment
By Mike Silverman

MD&M East – May 22-24, 2012, Philadelphia, PA

Ops A La Carte’s Mike Silverman will be giving a three hour class on "Medical Reliability Testing – Identifying Testing Requirements Early."

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Robust Design & Reliability

      I delivered a webinar recently  to  describe   the  differences and similarities between robust design (RD)  activities and reliability engineering (RE)  activities in hardware product development .  A survey we took from   several hundred attendees indicated a diversity of opinions. About half the participants indicated they did not differentiate at all between the two methodologies.  Approximately 20 % indicated they did differentiate between the two methodologies, and about 30% indicated that they did not know.

I was quite surprised at the result, especially since participants came  from  working quality engineers, reliability engineers, engineering directors, system engineers, etc.  Somewhere along the way,  the  differences and similarities between the two seem to have become muddled.  Below I have    collected just twelve of the many ways in which the activities are different:

 

RD 1  Focus on design  transfer functions, and  ideal function development

RE 1  Focus on design dysfunction, failure modes, failure times, mechanisms of failure

 

RD 2   Engineering focus, empirical  models, generic models , statistics.

RE 2    Mechanistic understanding, physical models,  science oriented  approach.

 

RD3  Optimization of input-output functions with verification testing requirement

RE3  Characterization of natural phenomena with root cause analysis and  countermeasure decisions

 

RD4  Orthogonal array testing, design of experiments planning

RE4   Life tests , accelerated life tests, highly accelerated tests, accelerated degradation tests, survival  methods

 

RD5   Multitude of control, noise, and signal factor  combinations for reducing sensitivity to noise and amplifying sensitivity to signal

RE5   Single factor testing,  some multifactor testing ,   fixed design with  noise factors,  acceleration factors

 

RD6   Actively change design parameters to improve insensitivity to noise factors, and sensitivity to signal factors

RE6   Design-Build-Test-Fix cycles for reliability growth

 

RD7   Failure inspection only with verification testing of improved functions

RE7   Design out failure mechanisms, reduce variation in product strength. Reduce the effect of usage/environment

 

RD8  Synergy with axiomatic design methodology including ideal design, and simpler design

RE8   Simplify design complexity for reliability improvement.  Reuse reliable hardware .

RD9   Hierarchy of quantitative design   limits including functional limits, spec limits, control limits, adjustment limits

RE9   Identify & Increase design margins, HALT & HASS testing to flesh out design weaknesses.   Temperature & vibration stressors predominate

 

RD10   Measurement system and response selection paramount

RE10   Time-to-failure quantitative measurements supported by analytic   methods

 

RD11  Ideal function development for energy relate measures

RE11  Fitting distributions to stochastic failure time data.  Time compression by stress application

 

 

RD12  Compound noise factors largest stress.  Reduce variability to noise factors by interaction between noise and control factors, signal and noise factor.

RE12  HALT & HASS highly accelerated  testing to reveal design vulnerabilities and expand margins.  Root cause exploration and mitigation

 

There are many other differences of course, but this list should start the conversation .  I  would invite bloggers to submit their own opinions  and  lists of differences (and similarities) .

Louis LaVallee

Sr. Reliability Consultant

Ops a la Carte

 

 

SMTA Conference on Soldering and Reliability – May 15-18, 2012, Toronto

Ops A La Carte’s Peter Arrowsmith will be giving a presentation at this conference on "Improving Product Reliability Using Accelerated Stress Testing".

For more info, please Contact Us

IPC Conference on Test & Inspection

April 15, 2012 | Leave a Comment
By Mike Silverman

IPC Conference on Test & Inspection – May 15-17, 2012, Costa Mesa, CA

Ops A La Carte will be giving a presentation at this conference on "New Techniques for More Effective ESS".

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2012 Reliability Symposium

April 7, 2012 | Leave a Comment
By Mike Silverman

May 7-11, 2012 in Santa Clara, California and via webinar

TRACK ONE – DFX TOOLS
Design for Reliability (DfR): May 7-8
Design for 6 Sigma (DfSS): May 9
Design for Mechanical Reliability (DfMR): May 10
Design for Warranty (DfW): May 11 morning
Design for Software Reliability (DfS): May 11 afternoon

TRACK TWO – REL TOOLS: ALT/DOE/RCA
Design of Experiments (DOE): May 7-8
Best Accelerated Reliability Tests (BART): May 9-10
Root Cause Analysis (RCA): May 11

Each attendee will receive a copy of Mike’s book "How Reliability Is Your Product: 50 Ways to Improve Product Reliability"

Location: 990 Richard Ave, Suite 101, Santa Clara, CA 95050 and via webinar
Price: $1195 for each 2 day course, $695 for each 1 day course, $395 for each 1/2 day course.25% discount for seminars taken via web-conference
Group Rates: Every 5th registrant (or the 5th day for one registrant) is free

You can Find Out More Here.

Design for Robustness

March 26, 2012 | Leave a Comment
By Mike Silverman

FREE WEBINAR on Design for Robustness, Wed, April 4, 2012, 8:30am-9:30am PST
Click here to REGISTER

Robust Design (RD) Methodology is discussed for hardware development. We will compare with reliability engineering (RE) tools and practices, and highlight differences and similarities. We will present proximity to ideal function for robust design and compare to physics of failure and other reliability modeling and prediction approaches. We will show measurement selection to strongly differentiates RD and reliability engineering methods. We will show how to get the most from each methodology and show pitfalls for each set of practices. This webinar will be a lead in to Lou’s symposium classes DOE and DFSS.

REGISTER.

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