2014 ARS, Asia Pacific: Shanghai

Transcription

1 2014 ARS, Asia Pacific: Shanghai Blue Room, Begins at 9:10 AM, Friday, November 7th Design for Reliability (DFR): Key Process Elements and the Application of Reliability Demonstration Tests Within the DFR Process Richard B. Ramirez, CRE, CQE SONOS Inc.

2 The following presentation was delivered at the: PRESENTATION SLIDES International Applied Reliability Symposium, Asia Pacific November 5-7, 2014: Shanghai, China The International Applied Reliability Symposium (ARS) is intended to be a forum for reliability and maintainability practitioners within industry and government to discuss their success stories and lessons learned regarding the application of reliability techniques to meet real world challenges. Each year, the ARS issues an open "Call for Presentations" at and the presentations delivered at the Symposium are selected on the basis of the presentation proposals received. Although the ARS may edit the presentation materials as needed to make them ready to print, the content of the presentation is solely the responsibility of the author. Publication of these presentation materials in the ARS Proceedings does not imply that the information and methods described in the presentation have been verified or endorsed by the ARS and/or its organizers. The publication of these materials in the ARS presentation format is Copyright 2014 by the ARS, All Rights Reserved.

3 Design for Reliability (DFR) Agenda Rick Ramirez, SONOS Inc. Blue Room 5 min 5 min 15 min 15 min 5 min 5 min 10 min Slide Number: 2 Need Reliability?? Design for Reliability (DFR) Intro. DFR Strategies DFR 7 Step Process Application of Reliability Demonstration Testing (RDT) Field Data Feedback to RDT & DFR Process Summary Questions Rick Ramirez, SONOS Inc. Blue Room Slide Number: 3 Three Basic Underlying Concepts in a DFR Framework Without Reliability Reliability must be designed into products and processes, using the best available sciencebased methods. 2. Knowing how to calculate reliability is important, but knowing how to achieve reliability is more important. 3. Design for Reliability practices must begin early in the design process and must be well integrated into the overall product development cycle. Rick Ramirez, SONOS Inc. Blue Room Slide Number: 4 1. Rick Ramirez, SONOS Inc. Blue Room Slide Number: 5

4 Design for Reliability Design for Reliability Strategies You cannot Test In Reliability or Inspect In Reliability - - you must Design In Reliability Reliability Example: Light Bulb Tech. for Light Fixture Design Define & develop product usage model for Design. Design out failure mechanisms. Reduce variation in product strength. Reduce the effect of usage/environment. Incandescent Light Bulb: Very thin tungsten filament that is housed inside a glass sphere. Characteristic Life Range: 750 to 1,000 hours. Generates extra heat that wastes energy. Fluorescent Light Bulb: Electrodes and a gas containing argon and mercury vapor with phosphor coated glass. Characteristic Life Range: 7,500 to 10,000 hours. Operates at cooler temperatures and is 4 to 6 times more energy efficient. LED Light Bulb: Light Emitting Diode technology; Characteristic Life Range: 75,000 to 100,000 hrs. Operates at cooler temps, 8x to 10x more energy efficient Slide Number: 6 Increase design margins. Reduce Reliability Risk Reliability Monitoring & Diagnostics Reduce the number of failure and/or error opportunities (part count and/or sw code reduction). For long usage life products with wear-out part characteristics, develop optimum preventative maintenance (PM) program. Product or System Benchmarking to set design & reliability goals. Slide Number: 7 Reliability Strategy Comparison Design for Reliability (DFR) Process {7 Key Process Steps} Tesla Motors 3-phase AC induction Motor & Gearbox comparison to conventional internal combustion engine & transmission. Develop & Define Reliability Requirements Set Reliability Specifications Tesla Motor & Gearbox: 17 moving parts Internal combustion engine & transmission: 250 to 600 moving parts depending on number of cylinders and gears Simpler motor technology with significant reduced part count result in 8X to 10X more reliable motor and gearbox design with less preventative & corrective maintenance actions. Slide Number: 8 Identify High Reliability Risk Areas in Proposed Design Reliability Analysis & Assessment of Proposed Design Reliability Test, Quantify, & Reliability Design Improvement Validate Reliability Control of Reliability [On-Going Reliability (ORT) ] Slide Number: 9

5 1. Develop & Define Reliability Requirements 1.2 Inherent Reliability Characteristics of Technology & Design Architecture Customer Usage Model Inherent Reliability Characteristics of Technology & Design Architecture Competitive Benchmarking Customer (VOC) & Product Surveys Historical Reliability Data Sources Quality Function Deployment (QFD) Diagnostics and/or Built-in-Test capabilities Supplier data sheets and Reliability Test data Slide Number: 10 Stress/Strength analysis Tolerance & worst case analysis DFX analysis Derating principles Part & material selection Robustness & Margin testing/evaluations Critical design input parameter evaluation using DOE, Taguchi, modeling such as Monte Carlo, FEA, CFD modeling/simulations Human Factor & Human Error Reliability Considerations Software Algorithm evaluation, review, & verification Theory of Operation Reliability Centered Maintenance (RCM) Analysis Develop Design for Reliability (DfR) Guidelines for Hardware and Software development. Slide Number: 11 Don t Be an Average Engineer Be a Six Sigma Engineer Average Stress (stress) Failure Likelihood Strength = 2x Avg. Stress 3 (Stress) Strength = [ (stress) +3 (stress] + 3 (strength) 3 (strength) Know Your Stress & Strength Variability Slide Number: Set Reliability Specifications Set Operational & Functional Specifications Define the various operation usage profiles Operating Environmental Specifications Non-operating/storage Specifications Durability/Abuse/Accidental specifications and detection Reliability Allocation Specifications Maintainability Allocation Specifications Slide Number: 13

6 3. Identify High Reliability Risk Areas in Proposed Design 4. Reliability Analysis & Assessment or Proposed Design Change Point Analysis RBD Baseline Reliability analysis & identify Reliability Opportunities Reliability Risk Assessment Analysis Physics of Failure (POF) analysis of known or expected failure modes Reliability Block Diagram Model analysis Modeling/Simulations of design (FEA, CFD, Solid Modeling, DfR Sherlock PWA analysis, etc.) DFMEA Fault Tree Analysis Design History File reviews Part or subsystem Critical to Reliability (CTR) identification & requirements Slide Number: 14 Reliability Prediction using Mil-Spec 217, 217Plus, or Telcordia SR-332 for PCBA s. Variation Sensitivity Analysis (ANOVA, Tolerance analysis) Design of Experiments on design parameter criticality and optimization opportunities. Monte Carlo Simulations & Statistical Modeling, Markov Analysis System Maintainability & Availability Analysis Slide Number: Reliability Test, Quantify & Reliability Design Improvement 6. Validate System Reliability Margin, HALT, Defect Discovery Tests Test Acceleration Factor Development Component or subsystem Reliability Demonstration Tests Component & subsystem Design Verification Tests (DVT) DOE tests for Reliability & Design improvements Preliminary Compliance Tests (Regulatory, Standards, Safety testing) Reliability Growth Testing FRACAS reporting system Slide Number: 16 System Level Reliability Demonstration Test Reliability Block Diagram model Validation Critical Supplier Subsystem Validation Tests System (DVT) Verification & Qualification Tests Compliance/Certification Tests System Validation Tests Slide Number: 17

7 7. Control Reliability On-Going Reliability Tests (ORT) Application of Reliability Demonstration Testing to the Product Development Life Cycle Process FMEA Identify KPIV (Key Process Input Variables) ESS/HASS, Burn-in stress screen tests (100%) HASA stress audit (sample tests) RDT test audit Supplier Audits Statistical Process Control (SPC) Warranty/Repair Analysis, Failure Analysis & CAPA program/process RBD model and DFMEA design updates Maintainability & Availability Analysis updates Slide Number: 18 Slide Number: Key Quality/Reliability Vision Implementation Step Product Development Reliability Plan Flowchart System/Subsystem Specifications Closing the feedback loop on System Reliability Demonstration Tests (RDT) with actual field return/repair data allows a continuous improvement process that hones in on our Corporate & Customer Reliability Vision. Slide Number: 20 Analysis/Prediction Models Design Reviews Subsystem Margin Tests Subsystem RDT Tests Analyze Test Data Reliability Block Diagram Model Subsystem Design Modifications System Prototype Build System RDT Test Analyze Test Data System Design Modifications Product Release Field Repair Data/Analysis Prod. Design Change Updates/Test Slide Number: 21

8 Product Reliability Definitions Customer Use Model Key Categories Reliability: the ability of an item to perform a required function under stated conditions for a stated period of time. (O Conner) Reliability: the probability of an item performing required functions under a specific USAGE MODEL. (R. Ramirez) Slide Number: 22 Customer Expectation for Product Useful Life and Warranty Period Identify and Define Product or System Operational / Functionality Usage and Performance Range Identify and Define Critical Subsystem or Component Operational / Functionality Usage and Performance Range Define Customer Product Environmental Storage and Operational Environments Define Service, Maintenance, and Calibration Customer Expectations or Requirements Identify Customer Abuse, Misuse, and Accidental Usage Conditions with the Highest Probability of Occurrence. Slide Number: 23 Infusion Medical Device Module Customer Use Model Infusion Device Operating Use Model: 18 hrs/day avg. for 365 days/yr.; 6,570 hrs/yr. (Nominal) Useful Operating Life Duration: 10 years (65,700 hrs) Warranty Period: 1 year Key Product Operational Usage Parameters: Power On/Off cycles: 3,900 cycles/yr; 39,000 cycles/10 yr. life Product handling drops: 1/2wk; 26/yr. Product cleaning/disinfecting procedure: 1/wk; 52/yr. Battery Charges: 1/day; 365/yr. Programmed Infusions: 1,250/ yr. Key Subsystem Operational Usage Parameters: Touch Screen Presses: 55/day; 14,300/yr; Press force range: lbf. Front keypad Presses: 50/day; 13,000/yr. Module Attachment/Detachment cycles: 2,200/yr. Bar code scans: 12/day, 4,380/yr. Environmental Use Model: Operating Temp.: 5 to 40 C; Storage -20 to 60 C. Typical Customer Abuse Condition: Instrument Pole Stand trip impact; 3 to 5 ft. height impact Cable/cord pull : 5 to 15 lbf pull force Slide Number: 24 Common Test Acceleration Types Usage Rate Acceleration: Applicable to Finite Use over time accelerated to Continuous Use. Life-Stress Relationship Acceleration: Applicable where physics of failure indicate a life-stress relationship. Arrhenius, Eyring, Hallberg-Peck, Coffin-Manson, and Inverse Power Law are common relationships. Accelerated Life Data Analysis: Mathematical extrapolation methods applied to empirical accelerated tests to determine acceleration factor. Customer Warranty/Field Data and Accelerated Test Data Analysis: Use Extrapolation methods to determine acceleration factors of empirical acceleration tests with normal/field usage failure data. Recommended System or Product level Acceleration Factors for RDT testing range from a factor of 2 to 20. Slide Number: 25

9 Use Field/Warranty Data to Establish Failure Criteria BETA Trial and early warranty repair data pareto Slide Number: 26 Reliability Demonstration Test Plan Levels Component Level RDT - Test Critical Components to Design or System. - Component RDT tests are less expensive and take less test time than higher RDT levels. - Critical Component Reliability Test metrics provide data for Reliability Block Diagram model (RBD). Subsystem Level RDT -Critical Path Subsystem to Design or System -Moderate test expense and parallel testing improves schedule efficiency -Key Subsystem Reliability Test metrics provide data for RBD model -Multiple components or parts can identify multiple part and part interface failures not detectable at component level RDT. -Subsystem RDT tests are typically simpler to conduct failure investigations because there will be less troubleshooting layers and less parts in test than at product or system level RDT testing. Product or System Level RDT - Provides the overall Reliability Metric Data and Reliability Prediction - Identifies SW/subsystem/component interface & interaction failures/issues. - Product or System level RDT tests are the highest expense level for RDT testing and have the greater test time durations versus lower level RDT tests Slide Number: 27 Major RDT Test Sections Key Infusion Device System RDT Test Sections Baseline, Calibration & Inspection Section - Fit/Functionality & Performance Checkout - Manufacturing, Assembly & Installation Data Feedback Transportation/Shipping type handling Section - Package Design Feedback - Customer Open Box Experience Usage Rate Acceleration Test Sections - Operation Time and/or Cycle Event Acceleration Test Sections Life Stress Relationship Test Sections - Elevated Stress Test Sections Customer Abuse or Accidental Event Test Section - Previous Product Field/Warranty Investigation Feedback used to Design RDT Abuse Test Section - Design and Repair Center Data Feedback Slide Number: 28 RDT Baseline Tests Shipping/Handling/Storage Tests Instrument Disinfect/Cleaning Process Test Portable Hand Carry/Handling Drop Test Swinging Door Impact and Door Jam or Elevator Door Impact Test IV Pole and System Treadmill Test, Wall/Corner Impact Test, and IV Pole Snag/Tilt/Crash Test Handset and Cord Cable Pulls ESD Test at all customer handling and usage interfaces Critical Operational/Functional Daily Test Elevated Temperature Tests Periodic Calibration Tests Slide Number: 29

10 Reliability Block Diagram (RBD) Model Inputs PM System Reliability Block Diagram Reliability parameters determined from Customer Warranty/Repair data used for same or similar components or subsystems leveraged in new design with similar application and usage model. Reliability Prediction inputs, Analysis and/or simulation model inputs. Reliability parameters determined from component and subsystem RDT tests. System Level RDT provides the overall and top failure mode subsystem reliability parameters for the RBD model. Customer Warranty/Repair data provides the closed loop feedback and the final reliability parameters for the RBD model. Slide Number: 30 BlockSim Analysis SW Package PM System Reliability Goal PM 1 st Year System Reliability: (90.68%).99 1 st Year Probability of Failure: (9.32%) 20 PM Subsystems Modeled in Series Slide Number: 31 Warranty Field Data Feedback PDF Failure Distribution Analysis to Identify Key Design Modification Opportunities Slide Number: 32 AFR% Goal: 1.0% Slide Number: 33

11 Warranty Field Data Feedback What was Predicted and Realized in Field Return Data Summary 1 st year Field Return AFR% of 3.87% was well within the RDT predicted AFR% range of % and a nominal of 4.25%. Sensor 1 failures and SW related failures were the top 2 failures for both the Field Return data and the RDT predicted data. 5 of 6 top RDT predicted failures were reported in Field Return data. Early Engineering Change Orders to correct RDT issues improved the Field AFR% in the 2 nd half of the 1 st year. Slide Number: 34 Design for Reliability (DFR) is a process that needs to start from the initial design concept phase to develop the intrinsic design genes and continues throughout the design life cycle. The DFR 7 step process and the key menu of subprocesses, methodologies, and tools were reviewed. Application of the RDT process within a DFR plan was presented. Field Return analysis feedback was used to compare predictions & improve the product and DFR process. Slide Number: 35 Q & A Period Reference Information Norman B. Fuqua, Reliability Engineering for Electronic Design, Marcel Dekker, Patrick O Conner, Practical Reliability Engineering 4 th ed., John Wiley & Sons, Slide Number: 36 Wortman, et al., CRE Primer, Quality Council of Indiana, Wortman, Carlson, et al., CQE Primer, Quality Council of Indiana, ReliaSoft, Fundamentals of Design for Reliability RS 560 Course Notes, Slide Number: 37

12 Richard B. Ramirez Rick Ramirez is currently a Sr. Principal Reliability Engineer for ViaSat Corporation in Carlsbad, CA. Rick has developed and introduced Reliability Processes, tools, and procedures at ViaSat that support R&D development from the early steps of product development and throughout the product life cycle. He has combined experience as a R&D engineer, Quality engineer, and Reliability engineer in the Aerospace, Telecommunications/SatCom, Computer, Electronics, and Medical Industries. Rick holds a BSME from Southern Methodist University (SMU) and a MSME from Massachusetts Institute of Technology (MIT). He has current ASQ certifications as a Reliability Engineer and a Quality Engineer. Contact at richard.ramirez@viasat.com Slide Number: 38