The book Software Estimation and Requirements for the importance of software engineering is well known in various engineering fields. It provides a logical method of explaining various complicated concepts and step wise methods to explain essential topics. Each chapter is well supported with the necessary illustrations. All the chapters in the book are arranged in a proper sequence that permits each topic to build upon earlier studies. SOFTWARE ENGINEERING is a critical research area. The techniques developed in this area so far require to be summarised appropriately. In this book, the fundamental theories of these techniques are introduced.