 He was the innovator and architect of the CADES software engineering system that was the foundation of VME/B development activities for over 20 years, and he led its development team until 1977.In designing the initial architecture of the CADES environment, Pearson looked to parallels with the leading hardware computer-aided design systems of the time, even attempting the use of graphics in the design process.CADES was one of the first effective software engineering environments to be used for the development of large-scale software.