The present globalization and market economy have brought out quality and reliability of products as an important driver to gain competitive advantage. Reliability and quality are the core issues to be addressed during the design and operation of engineering systems like nuclear power plants, security systems, transportation systems, software systems and systems of strategic importance. The issues are the key to the growth of an economy in the industrialized world. The book deals with varied themes of system reliability modeling, applied six sigma methodology, fuzzy sets application in reliability modeling, software reliability growth modeling, RCM programmes, optimal maintenance, wireless communication reliability, optimization issues in reliability, and the usage of advanced computational intelligence e.g artificial neural networks for complex system reliability evaluation. The book is, therefore, aimed at addressing the key issues for engineers working in service industries, strategic sectors of power, IT security, nuclear, defence, telecom, and graduate students and researchers in universities and laboratories.