Winston W. Royce

Born in 1929, Royce entered the California Institute of Technology, where he received his BS in physics, his MS in aeronautical engineering and in 1959 his PhD in aeronautical engineering under Julian David Cole with the thesis Transonic flow over a non-lifting, slender body of revolution. Royce had begun his career as assistant professor at the California Institute of Technology. In 1961 he started as project manager in the aerospace division of TRW. His first project concerned the design of a mission planning and orbit selection system for spacecraft. In the following years he was involved in the research and development of several large and complex software systems, and started developing new methodologies for improving the management of software project. In 1970 he published his influential article "Managing the development of large software systems", in which he presented several project management models, including what we now know as waterfall, iterative, and agile. During the 1980s he was director at Lockheed Software Technology Center in Austin, Texas. He retired in 1994 and died the following year at his home in Clifton, Virginia. His eldest son is Walker Royce, Chief Software Economist of IBM's Rational division, and author of Software Project Management: A Unified Framework, and a principal contributor to the management philosophy inherent in the IBM Rational Unified Process. == Work ==

"Managing the development of large software systems" The Waterfall model for software development is mistakenly attributed to Royce. Barry Boehm wrote in 1987: In fact, Royce demonstrated that while the development of large software systems required a more thorough approach, there was inherent risk in a single-pass sequential approach. He proposed an iterative approach and advocated that projects should pass through this at least twice. Royce started his 1970 article "Managing the development of large software systems" with a statement about the origin of his ideas: Royce had determined that the development of computer programs regardless of size or complexity could be split into two development stages: Analysis and Coding. For small software development projects these two steps were sufficient, but not for the development of larger software systems. These require many additional steps back and forth, which gives the development an iterative character. nor advocated it as an effective methodology. The earliest use of the term "waterfall" may have been a 1976 paper by Bell and Thayer. Royce pictured the waterfall model with the following seven steps: According to Richard H. Thayer, emeritus professor in software engineering at California State University, Sacramento, "applying system engineering principles specifically to the development of large, complex software systems provides a powerful tool for process and product management." According to Philippe Kruchten et al. (2006) this article was the first "to position software architecture — in both title and perspective — between technology and process." ==See also==

Royce published several books and articles. Books • 1959. Transonic flow over a non-lifting, slender body of revolution. Pasadena : California Institute of Technology, 1959. • 1997. Software Engineering Project Management. 2nd edition. With R. Thayer & Ed Yourdon. Articles, a selection: • 1970. "Managing the Development of Large Software Systems", Proceedings of IEEE WESCON 26 (August): 1–9. • 1989. "Lockheed's Software Technology Center". In: Modern software engineering, foundations and current perspectives. Peter A. Ng (ed.). Van Nostrand Reinhold Co. p. 561–578. • 1990. "'Dr. Win Royce Process Round Table Aug. 10th 1990 • 1991. "Current Problems." In: Aerospace Software Engineering, edited by Christine Anderson and Merlin Dorfman, 5–15. Washington, D.C.: American Institute of Aeronautics and Astronautics. • 1991. "Software Architecture: Integrating Process and Technology", with Walker Royce in TRW Quest, vol. 14, no. 1, p. 2–15. • 1992. "[http://users.ece.utexas.edu/~perry/education/SE-Intro/luqi-sw91.pdf Status Report: Computer-Aided Prototyping". With Walker Royce. In: IEEE Software Vol 9 (6): p. 77–81 ==References==