Our Company is a privately-held professional reliabilityengineering firm founded in 2001 and headquartered in SantaClara, California with offices in China, India and Singapore. was named one of the top 10fastest growing, privately-held companies inthe Silicon Valley in 2006 and 2009 by theSan Jose Business Journal. is a solid company that hasbeen profitable every quarter since itsinception due to its outstanding reputation,customer value and scalable business model.
Our Team is made up of a group ofhighly accomplished Reliability Consultants.Each of our consultants has 15+ years ofReliability Engineering and ReliabilityManagement experience in variousindustries.We tap a large network of labs, test facilities,and talented engineering professionals toquickly assemble resources to supplementyour organization.
• Ops Solutions – Ops provides end-to-end solutions that target the corporateproduct reliability objectives• Ops Individual “A La Carte” Consulting – Ops identifies and solves themissing key ingredients needed for a fully integrated reliable product• Ops Training – Ops’ highly specialized leaders and experts in the industrytrain others in both standard and customized training seminars• Ops Testing – Ops’ state-of-the-artprovides comprehensive testing services
assists clients in developing and executing any and all elementsof Reliability through the Product Life Cycle. has the unique ability to assess a product and understand thekey reliability elements necessary to measure/improve product performanceand customer satisfaction. pioneered “Reliability Integration” – using multiple tools inconjunction throughout each client’s organization to greatly increase the powerand value of any Reliability Program.
HALT Calculator Field Failure Rate Estimate - % of Failures/Year Input Matrix Data Verifiy MTBF (in Hrs) = 40,000 OK Key Product Thermal (Hot in °C) = 94 OK User input Product Thermal (Cold in °C) = -58 OK Calculated Product Vibration (in Grms) = 80 OK Selection Prod Published Spec Level (see below) = 3 OK Data Validity Number of HALT Samples = 4 OK Steady State AFR, % (HALT Only) = 1.06Steady State Field MTBF, Hrs (HALT Only) = 822954 Lower 90% HALT Confidence Limit = 443657 Upper 90% HALT Confidence Limit = 1691518 Published Spec Level # Guard Band Limits 0 to +40 1 Consumer -30 to +80 0 to +50 2 Hi-end Consumer -30 to +100 -10 to +50 3 Hi Performance -40 to +110 -20 to +50 4 Critical Application -50 to +110 -25 to +65 5 Sheltered -50 to +110 -40 to +85 6 All Outdoor -65 to +110
The “Ideal” HASS Profile for wide operating limitsUOL Fast Rate Thermal Make dwells long enough to execute diagnostic suite. Execute diagnostics during entire profile.S It is highlyP recommended toE t combine six-axisC vibration, tickle vibration, power cycling, other stresses with thermal. Powered on monitoring is essential.LOL
The “Ideal” HASS Profile for narrow operating limitsUDL Make dwells long enough to execute diagnostic suite. Execute diagnostics during entire profile.UOL Fast Rate ThermalSPE tC Slow Rate ThermalLOL It is highly recommended to combine six- axis vibration, tickle vibration, power cycling, other stresses with thermal.LDL Powered on monitoring is essential.
DfR Training FormulasAssessment Formulas Gap = Goals – Current CapabilitiesModeling FormulasFailure Distributions: Exponential Distribution Weibull DistributionSeries: RS=RA*RB*…*RN T=1+2+…+NParallel: RS = RA+ RB – (RARB) (for two components) General formula for N, different, parallel components: General formula for N, identical parallel components: Ops A La Carte LLC www.opsalacarte.com (408) 654-0499 Pg 1 of 6 (v1)
DfR Training FormulasActive Redundancy Formulas: k=1Reliability Prediction FormulasP=B * Q * E* S* T* FYM where Q=Quality Factor E =Environmental Factor S =Electrical Stress Factor S = em(P1 – P0) where P1 = applied stress percentage P0 = reference stress (50%) m = fitting parameter for particular curve T =Thermal Factor FYM =First Year Multiplier (Infant Mortality) Factor Ops A La Carte LLC www.opsalacarte.com (408) 654-0499 Pg 2 of 6 (v1)
DfR Training FormulasMaintainability Formulas n n MTTR i*t i) / i) i=1 i=1 where n = number of subsystems i = Failure Rate of the ith system t i = Time to repair the ith systemAvailability Formulas Availability = MTBF / (MTBF + MTTR)Series Availability n A = A = A1*A2*…*AN i=1Parallel Availability n A = 1- U = 1 – [(1-A1)*(1-A2)*…**1-AN)] i=1 where U=Unavailability=1-Availability Ops A La Carte LLC www.opsalacarte.com (408) 654-0499 Pg 3 of 6 (v1)
DfR Training FormulasAccelerated Reliability Testing FormulasMinor’s Rule: Dn where, D= Cumulative Fatigue Damage n= Number of Stress Cycles = Stress = Empirically Derived (8<b<12) E 1 1 Arrhenius Equation: AF exp a T T where k u t AF=Acceleration Factor Ea= Activation Energy K=Boltzman constant = 8.62 x 10-5 Tu=Reference Temperature, in Kelvin Ti=Temperature of Operating Environment, in Kelvin Ea 1 1 Accelerated Temperature/Voltage AFoverall e k To Ts e Vs Vo Where, AF = acceleration factor Ea = activation energy k = Boltzmann’s Constant To = Operating Temperature Ts = Qualification Temperature Vs = Qualification Voltage Vo = Operating VoltageHallberg-Peck Model RH s E 1 1 3 AF e a (temperature/humidity) RHo k To Ts Where, AF = acceleration factor Ea = activation energy k = Boltzmann’s Constant To = Operating Temperature Ts = Qualification Temperature RHs = Qualification Relative Humidity RHo = Operating Relative Humidity 1Modified Coffin-Manson T 1.9 F 3 AF s o e0.01Ts To F (temperature/ramp rate) To sNOTE: For SnPb solder joints Where, AF = acceleration factor ΔTo = operating use thermal cycle temperature change ΔTs = stress test thermal cycle temperature change Fo = operating use thermal cycling frequency Fs = stress test thermal cycling frequency To = Operating Temperature Ts = Qualification Temperature Ops A La Carte LLC www.opsalacarte.com (408) 654-0499 Pg 4 of 6 (v1)
DfR Training FormulasOps A La Carte LLC www.opsalacarte.com (408) 654-0499 Pg 5 of 6 (v1)
DfR Training FormulasStatistics Formulas (Used in Highly Accelerated Stress Auditing)Sample Size: P(d) = 1 - (1 - p)n where, 1 is the probability of success, P(d) is the probability that a certain defect will be detected, p is the probability failure or of any unit having the defect and, n is the sample size.Sample Size for Failure Free Testing: n = ln(1 – confidence level) / ln(reliability) RL = 1/n where RL = Lower Reliability =1-confidence n=sample sizeReliability Formula Using Acceleration Factor R=e-t/AF where AF=Acceleration Factor t=test time =failure rateReliability Formula for a Weibull Distribution R=(e-t/AF) where AF=Acceleration Factor t=test time =failure rate =The Beta (or Shape) Parameter Ops A La Carte LLC www.opsalacarte.com (408) 654-0499 Pg 6 of 6 (v1)
DfR Training Glossary of AcronymsAFR Annualized Failure RateALT Accelerated Life TestCAPA Corrective and Preventive ActionDfM Design for ManufacturabilityDfR Design for ReliabilityDfSS Design for Six SigmaDfT Design for TestabilityDfX Design for “X”DOA Dead on ArrivalDoE Design of ExperimentsDVT Design Verification TestingFEA Finite Element AnalysisFMEA Failure Modes and Effects AnalysisFMECA Failure Modes, Effects, and Criticality AnalysisFRACAS Failure Reporting, Analysis, and Corrective Action SystemFT Fault ToleranceFTA Fault Tree AnalysisFTL Fundamental Technological LimitGRMS Gravity Root Mean Squared (a measure of level of vibration)HALT Highly Accelerated Life TestingHASA Highly Accelerated Stress AuditingHASS Highly Accelerated Stress ScreeningHLD High Level DesignHW HardwareIR InfraredLCC Life Cycle CostLOL/UOL Lower Operating Limit/Upper Operating LimitLDL/UDL Lower Destruct Limit/Upper Destruct LimitLLD Low Level DesignMAMT Mean Active Maintenance TimeMEOST Multiple Environment Over Stress TestingMTBF Mean Time Between FailureMTTF Mean Time to FailureMTTR Mean Time to RepairMR Margin ReleaseNDE Non-Destructive EvaluationNTF No Trouble Found Ops A La Carte LLC www.opsalacarte.com (408) 654-0499 Pg 1 of 2
DfR Training Glossary of AcronymsODM Original Design ManufacturerORT On-Going Reliability TestingPCA Printed Circuit AssemblyPCB Printed Circuit BoardPWA Printed Wiring AssemblyPWB Printed Wiring BoardPDS Probabilistic Design SystemPM Preventive MaintenancePRAT Production Reliability Acceptance TestingPRST Probability Ratio Sequential TestingRCA Root Cause AnalysisRCCA Root Cause Corrective ActionRDB Reliability Block DiagrammingRDT Reliability Demonstration TestingRGTD Reliability Growth TestingRoHS Restriction of Hazardous SubstancesROI Return on InvestmentRPN Risk Priority Number (used in FMEAs)S-N Curve Stress vs. Number of CyclesSAM Scanning Acoustic MicroscopySQUID Superconducting Quantum Interference Device MicroscopySTRIFE Stress for LifeSW SoftwareTDR Time Domain ReflectometryVOL/VDL Vibration Operating Limit/Vibration Destruct LimitWEEE Waste Electrical and Electronic Equipment Ops A La Carte LLC www.opsalacarte.com (408) 654-0499 Pg 2 of 2