Modern eng. systems have become increasingly complex to design and build while the demand for reliability, quality and cost effective development continues. Reliability is one of the most important attributes in such critical systems as defense system, aerospace, real time control and medical application as well as commercial systems. Growing International competition has increased the need for all engineers and designers to ensure a level of quality and reliability of their product. In today's marketplace, product quality is necessary in order to stay in business but in tomorrow's marketplace, reliability will be the norm. Reliability is the continuation of quality over time. It is time period over which a product meets the standards of quality for the period of expected use. Quality is now the standard for doing business. In today's marketplace and beyond, reliability will be the standard for doing business. The quality revolution is not over;it has just evolved into the reliability revolution, giving rise to many questions. This monograph is an attempt to answer some of the relevant questions in the field of Reliability management.