1 22.9.2008

Highly Accelerated Life Testing HALT

Joni Kiiski, KONE Technology Organisation / Reliability LaboratoryReliability Manager, Feedback26/09/2008

2 9/22/2008 KOTEL / CEEES Conference

AgendaManagement of Verified Environmental Stresses26/09/2008

1. KONE and KONE Reliability Laboratory in brief2. HALT terminology and its application in KONE3. HALT Case4. Summary part

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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

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KONE Care for Life

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.

Full replacement

Modern ization

Installation

Service repairs

5 22.9.2008

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

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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

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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

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Aligning HALT elements to Achieve Operational Excellence

Physics of Failure

Statistics

HALT

People

ProcessChamber & Data loggers

Customer-Driven Hard Core Engineering

HALT

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HALT Technique

� HALT uses higher stresses than in field conditions, specifications are exceeded on purpose

� 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

ProductSpecs

Stress

UpperDestruct

Limit

LowerDestruct

Limit

Destruct MarginDestruct Margin

UpperOperating

Limit

LowerOperating

Limit

Margin

Operating

MarginOperating

LowerDestruct

Limit

ProductSpecs

Stress

UpperDestruct

Limit

Destruct MarginDestruct Margin

Margin

OperatingMargin

Operating

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HALT Case

Root Cause of failure

Improper fixing design of printed circuit board (sensitive for resonance frequency caused by

transportation)

Failure Mode

Broken capacitor pin

Customer observation (effect on elevator level)

Early failure during commissioning phase, additional costs

Effect of failure

Ripple voltage on 15,8 V supply voltage

T im e 1 6 :0 5 :3 2 1 6 :0 5 :4 4 1 6 :0 5 :5 7 1 6 :0 6 :0 9 1 6 :0 6 :2 2 1 6 :0 6 :3 4

3 0 2 5 2 0 1 5 1 0

5 0

3 0 2 5 2 0 1 5 1 0

5 0

2 0 ,0 1 7 ,5 1 5 ,0 1 2 ,5 1 0 ,0

7 ,5 5 ,0 2 ,5 0 ,0

+ 5 V + 2 4 V + -1 2 V + -1 5 V + -5 V D C 1 5 .8 V D C M o to r F a n N T C V D D _ 2 4 P O

c p u Y 1 : Y 2 : C h a n n e l: 1 5 .8 V D C

1 8 ,4 9 V 1 7 ,8 1 V

P o w e r b re a k

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HALT needs to be linked to Product Development Processes

• 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...)

Product Product TechnologyTechnology

StartStart SpecificationSpecification FunctionalityFunctionality ProcessesProcesses ReleaseRelease ClosingClosing

Business Business CaseCase

ReliabilityReliability

SafetySafety

Design Verification Product Verification

Process Validation Lessons Learned

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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

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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