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

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

3. 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

4. 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

5. 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

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

7. 1.3 Pattern of Failure
1.3.1 component failure

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

10. Show relative frequency diagram:

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

15. 1.4 Factor of Safety and reliability
S=150k(lb/in2), L=75k(lb/in2)

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