The consumption and disposal of electrical and electronic equipment forms a dynamic sys-tem. 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 dura-bles are discussed, namely the “delay model” approach and the “reverse diffusion model” ap-proach. 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 fur-ther improvements to both modelling approaches.