This report presents the structure and the possible uses of a long range system analysis tool which models the evolution of the energy needs of the Canadian pulp and paper industrial sector over a multi-decade time horizon. An illustration of the results obtainable through this modelling approach is given, based on the data concerning the Québec pulp and paper industry and more particularly the newsprint production sector. Also the usefulness and the feasibility of an extended model considering other resources than energy alone is discussed.