Dein Shaw PME, Tsing Hua University Design Reliability Dein Shaw PME, Tsing Hua University

Chapter 1 Introduction 1.1 Reliability history German V1, V2 rocket World war II Electronic tube Aeronautic radio, Inc, 1947 …….

1.2 Need of reliability in product design Huge amount of the parts are used for a complicate system. eg. $1 for design stage $ 10 after final release $100 at prototype $1000 at pre-production stage $10000 at production stage Design relate problems are greatest causes for product failure. 43% due t design, 30% operation and maintenance, 20% manufacturing, 7% miscellaneous factors

Reliability in the product design process Reliability tasks: Establishing reliability requirements definition Using reliability design standards/guides/checklist Allocation reliability Predicting reliability Reliability modeling Monitoring subcontractor/supplier reliability activities Performing failure modes effects and criticality analysis Monitoring reliability growth Accessing software reliability Environmental stress screening Preparing critical items list Performing electronic parts/circuits tolerance analysis

Reliability specialized and application areas Mechanical reliability Software reliability Human reliability Reliability optimization Reliability growth Structural reliability Reliability general Power system reliability Robot reliability and safety Life cycle coasting Maintainability

Term and definition Reliability Failure Maintainability Redundancy Active redundancy Availability Mean time to failure (exponential distribution) Useful life Mission time Human error Human reliability

1.3 Pattern of Failure 1.3.1 component failure

Example 1.1 automobile break (measured in miles of successful operation)

Show relative frequency diagram:

As will shown later, the standard deviation indicates a measure of the spread out of the life of break.

1.4 Factor of Safety and reliability S=150k(lb/in2), L=75k(lb/in2)

Problem: Find the U.S. military standard which are relate to reliability.