This work presents a "3 steps-2 aggregation levels" methodological approach for modelling the evolution of the hybrid demand order flow pattern over long time horizons. The hybrid demand is the result of the mutual interaction between the e-commerce and the traditional demand. Thus, its modelling requires a complex analysis at various aggregation levels. More specifically, the quantitative modelling and prediction of e-commerce demand is achieved, both at the market (e-sales turnover) and at the operational (order flow) levels. Then, the demand stemming from the traditional sales channels, modified by the e-commerce introduction is specified and formalised. The concurrent presence of dynamic processes and several uncertainty sources as well as the necessity to assess the impact of e-commerce induced demand modifications over a long time horizon justify the development of a demand scenario planning approach. (c) 2010 Elsevier B.V. All rights reserved.