Abstract: System of technologies can be characterized by their technical interaction among the components of the systems. The interaction has a significant effect on technological development.In this paper, a quantitative model for analysing systems of interacted technologies is proposed. The model is composed of two coupled nonlinear differential equations. The qualitative theory of differential equations is used to analyse the equilibrium points of the system and their stabilitiy.Some typical processes of technological development are given. The results show that the interaction among technologies has an important effect on the behavior of the system of technologies. This effect should be considered in decision making of technological development.

Key words: interaction, technology management, system analysis, deci-sion analysis