Aditya P Mathur is Professor, and Head, Department of Computer Science, Purdue University, West Lafayette, USA. In this book he brings over 30 years of experience in teaching, researching and consulting in software engineering. He is one of the founders of the department of Computer Science at BITS, Pilani, India where he designed, developed, and taught the first course on microprocessors to undergraduate students from his seminal book Introduction to Microprocessors. Dr. Mathur has been a prolific researcher with over 100 published works in international journals and conferences. His key contributions include a multilingual computer, the saturation effect in software testing, a theory of software cybernetics, and novel techniques for the estimation of software reliability.