This book is meant for postgraduate modules that cover lifetime data in reliability and survival analysis as taught in statistics, engineering statistics and medical statistics courses. It is helpful for researchers who wish to choose appropriate models and methods for analyzing lifetime data. There is an extensive discussion on the concept and role of ageing in choosing appropriate models for lifetime data, with a special emphasis on tests of exponentiality. There are interesting contributions related to the topics of ageing, tests for exponentiality, competing risks and repairable systems. A special feature of this book is that it introduces the public domain R-software and explains how it can be used in computations of methods discussed in the book. Contents: Ageing; Some Parametric Families of Probability Distributions; Parametric Analysis of Survival Data; Nonparametric Estimation of the Survival Function; Tests of Exponentiality; Two Sample Nonparametric Problems; Proportional Hazards Model: A Method of Regression; Analysis of Competing Risks; Repairable Systems. Key Features Special emphasis on ageing and tests of exponentiality and their role in choosing appropriate models for lifetime data Extensive discussion of classical parametric and nonparametric models and relevant inference Documentation of new results in ageing, testing for competing risks and repairable systems Readership: Graduate students, academics and researchers in probability and statistics, industrial engineering, decision sciences and bioinformatics.