Tabu Search with Strategic Oscillation for Improving Recollection Assignment Plans of Waste Electric and Electronic Equipment

Abstract: This paper studies a districting problem arising in the recollection of waste electrical and electronic equipment (WEEE). Given a set of recollection bins, where users return end-of-life electronic goods, located across a region or country, the design problem consists of assigning these bins to the companies who will be responsible for the recollection at a later stage. This assignment must meet certain planning and legal requirements such as a fair household distribution according to the market share of each company and a fair assignment based on the bin's infrastructure quality. According the the current WEEE II Directive, this assignment must be done in a such a way so as to avoid, to the best possible extent, regional monopolies. This is achieved by maximizing a dispersion function. A tabu search metaheuristic with advanced feature of strategic oscillation is proposed for this NP-hard combinatorial optimization problem. In addition, a few upper bounding schemes are developed and tested. The empirical work shows the effectiveness of the tabu search and each of its components over a wide set of instances from literature.