8. Assessing Product Reliability

8.2.	Assumptions/Prerequisites

This section describes how life distribution models and acceleration models are typically chosen. Several graphical and analytical methods for evaluating model fit are also discussed.

Detailed contents of Section 2

2. Assumptions/Prerequisites 

1. How do you choose an appropriate life distribution model? 
1. Based on failure mode 
2. Extreme value argument 
3. Multiplicative degradation argument 
4. Fatigue life (Birnbaum-Saunders) argument 
5. Empirical model fitting - distribution free (Kaplan-Meier) approach 
2. How do you plot reliability data? 
1. Probability plotting 
2. Hazard and cum hazard plotting 
3. Trend and growth plotting (Duane plots) 
3. How can you test reliability model assumptions? 
1. Visual tests 
2. Goodness of fit tests 
3. Likelihood ratio tests 
4. Trend tests
4. How do you choose an appropriate physical acceleration model? 
5. What models and assumptions are typically made when Bayesian methods are used for reliability evaluation?