Comparison of two multicriteria decision aid methods: Net Flow and Rough Set Methods in a high yield pulping process

This investigation presents a synthesis of two multicriteria analysis methods, Rough Set Method (RSM) and Net Flow Method (NFM), applied to the multicriteria optimisation for the manufacture of paper using jack pine as the source of fibres. This work is the result of a collaboration between different Canadian and French laboratories. The two optimisation methods, based on different approaches, are applied to the same Pareto domain of non-dominated operating conditions. The Rough Set Method (RSM) uses a set of decision rules that are based on the preferences of experts, when presented with a small set of diverse conditions extracted from the Pareto domain. These rules are then applied to the entire Pareto domain to determine the preferred zone of operation. In the Net Flow Method (NFM), the preferences of experts are defined with three threshold values and one set of weights that are used to classify the entire Pareto domain. The NFM is a hybrid of two methods between ELECTRE and PROMETHEE. To compare these two methods, they were used to optimise the identical process. Results clearly show that the two methods gave nearly identical optimal solutions and well within inherent experimental errors.