Technological change is a dynamic and multidimensional phenomenon involving substitution and diffusion of technologies. In this process new technologies are entered into the market while the old ones are displaced. Various models have been constructed to explore the principles of technology substitutions. In general there are two approaches in tackling the problem. The first approach is using the replacing factor as the measure of technology substitution assuming that it is a function of market share captured by the technology or/and the time elapsed since technology introduction into the economic system. The second approach models the competitive technologies penetration separately where their intrinsic and competitive effects are explicitly represented into the relevant models. The purpose of this paper is to review the existent modeling approaches of technology substitution and analyze the factors affecting the interrelationship between the competing technologies. Finally, the models under review will be used to describe the substitution of the dial-up by the broadband technology for internet connectivity purposes and the models’ fitting and forecasting performance is illustrated.