Software engineering is the application of engineering to the development of software in a systematic method. Notable definitions of software engineering include: 1.Tthe systematic application of scientific and technological knowledge, methods, and experience to the design, implementation, testing, and documentation of software"—The Bureau of Labor Statistics—IEEE Systems and software engineering - Vocabulary 2.The application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software"—IEEE Standard Glossary of Software Engineering Terminology 3.an engineering discipline that is concerned with all aspects of software production"—Ian Sommerville 4.the establishment and use of sound engineering principles in order to economically obtain software that is reliable and works efficiently on real machines"—Fritz Bauer