The consumption and disposal of electrical and electronic equipment forms a dynamic system. This paper applies system dynamics methodology to assess mass flows of end-of-life equipment. In the paper, two modelling approaches to forecasting disposal of consumer durables are discussed, namely the “delay model” approach and the “reverse diffusion model” approach. Applying the same dataset on the disposal of cathode ray tube personal computer monitors in Switzerland to both the approaches, the estimates and forecasts of the models are compared against real system data. The comparison provides an opportunity to discuss further improvements to both modelling approaches.