The work of designers in the 1960s was influenced by industry, as the debate on design evolved from an aesthetic function into active cooperation with industry. Designers had to work in a team with engineers and marketers, and design was perceived as one part of the product development process. In the early years, design management was strongly influenced by system science and the emergence of a design science (e.g. the "blooming period of design methodologies" in Germany, the US, and Great Britain), as its main contributors had backgrounds in architecture. Early discussions on design management were strongly influenced by Anglo-Saxon literature (e.g. Farr and Horst Rittel), methodological studies in Design Research (e.g. HfG Ulm and Christopher Alexander), and theories in business studies. Design management dealt with two main issues: