Highly Accelerated Life Testing HALT

Transcription

1 Highly Accelerated Life Testing HALT Joni Kiiski, KONE Technology Organisation / Reliability Laboratory Reliability Manager, Feedback 26/09/

2 Agenda Management of Verified Environmental Stresses 26/09/ KONE and KONE Reliability Laboratory in brief 2. HALT terminology and its application in KONE 3. HALT Case 4. Summary part 2 9/22/2008 KOTEL / CEEES Conference

3 About KONE KONE provides its customers with industry-leading elevators, escalators and innovative solutions for modernization and maintenance, and is one of the global leaders in its industry. Founded in Finland in 1910 Present in 50 countries through some 800 service centers Approx. 600,000 elevators and escalators under maintenance contract In 2007, KONE had annual net sales of EUR 4.1 billion and over 32,500 employees 3 9/22/2008 KOTEL / CEEES Conference

4 KONE Care for Life Full replacement Installation Modernization Service repairs KONE delivers a performance edge to it s customers by creating the best user experience with innovative People Flow solutions. People Flow solutions enable people to move smoothly, safely, comfortably and without waiting during whole life cycle. 4 9/22/2008 KOTEL / CEEES Conference

5 KONE Reliablity Laboratory in Brief Reliability Laboratory supports Product Development projects from concept development to product change management The goal of the Reliability Laboratory is: To Improve Product s Quality and Reliability Throughout the Life Cycle This becomes concrete in project specific Reliability Plans based on Design for Reliability DFR Process

6 Accelerated Stress Testing Terminology Based on qualitative Accelerated Stress Testing AST like Highly Accelerated Life Testing HALT potential design weaknesses can be found rapidly. Quantitative Accelerated Life Testing QALT is used to understand reliability figures. HALT term can be misleading because both probability to fail life of product and highly accelerated test factor remain unknown Application of HALT in KONE includes extreame cold and dry heat temperatures, rapid temperature changes, 6 degree of freedom vibration and combination of all of these 6 9/22/2008 KOTEL / CEEES Conference

7 Why HALT? Warranty time requirements are increasing Product and process complexity is increasing Product development time gets shorter Traditional reliability verification methods like Design FMEA or Failure Tree Analyses FTA cannot provide list of potential failure modes in resonable time concerning electronics Need for fast qualitative verification between different suppliers is increasing -> more detailed discussiond with suppliers having robust design vs product cost In order to understand Non defect Found NDF field failures 7 9/22/2008 KOTEL / CEEES Conference

8 Aligning HALT elements to Achieve Operational Excellence Customer-Driven Hard Core Engineering People HALT HALT Statistics Physics of Failure Chamber & Data loggers Process 8 9/22/2008 KOTEL / CEEES Conference

9 HALT Technique HALT uses higher stresses than in field conditions, specifications are exceeded on purpose Lower Destruct Limit Lower Operating Limit Operating Margin Destruct Margin Product Specs Upper Operating Limit Operating Margin Destruct Margin Upper Destruct Limit The stress magnitude when failure happens is not so important but failure modes is Effect of failure (severity) and operating margin is discussed when concidering corrective actions to add design robustness Lower Destruct Limit Operating Margin Destruct Margin Stress Product Specs Operating Margin Destruct Margin Upper Destruct Limit 9 9/22/2008 KOTEL / CEEES Conference Stress

10 HALT Case Customer observation (effect on elevator level) Early failure during commissioning phase, additional costs Effect of failure Ripple voltage on 15,8 V supply voltage Failure Mode Broken capacitor pin P o w e r b r e a k Root Cause of failure ,0 1 7,5 Improper fixing design of printed circuit board (sensitive for resonance frequency caused by transportation) 10 9/22/2008 KOTEL / CEEES Conference 1 5,0 1 2,5 1 0,0 7,5 5,0 2,5 0,0 1 6 :0 5 : :0 5 : :0 5 : :0 6 : :0 6 : :0 6 : V V V V V D C V D C M o to r F a n T im e N T C V D D _ 2 4 P O C h a n n e l: V D C Y 1 : 1 8,4 9 V Y 2 : 1 7,8 1 V

11 HALT needs to be linked to Product Development Processes Start Specification Functionality Processes Release Closing Business Case Product Technology Reliability Design Verification Product Verification Process Validation Lessons Learned Safety Design Verification (Re-Use Check, Blue Design Review, Feasibility Analysis for business based reliability targets, DFMEA, FTA, Reliability Plan, HALT...) Product Verification (Life Data Analysis, Approvals...) Process Validation (First Pilot Site Reviews, Warranty Analysis...) Lessons Learned (Reliability Plan Review, FRACAS...) 11 9/22/2008 KOTEL / CEEES Conference

12 Lessons Learned Process approach: Operational testing based on good planning and preparations together with project and HALT teams Root cause analysis Corrective actions Verification of corrective actions Documentation of lessons learned and utilization of findings to design guidelines etc HALT is far more easier when persons having experience from true field failures are participating for whole HALT process Earlier the better HALT process owner is a must 12 9/22/2008 KOTEL / CEEES Conference

13 Challengies Communication especially at the implementation phase Root Cause Analyses Utilization of HALT results in to manufacturing quality screening (HASS) Continuous improvement of internal HALT process 13 9/22/2008 KOTEL / CEEES Conference

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