A bi-objective model for sustainable logistics and operations planning of WEEE recovery

Abstract

The Triple-bottom-line concept suggests that firms must consider theenvironmental and social impacts of their decisions, beside the economicaspects. Hence, the sustainability of the firms’ operations can be reached. Thepurpose of this study is to develop a bi-objective, multi-product and multi-period mixed-integer model for the operations planning of electrical-electronicwaste (WEEE) recovery facilities, by considering social (workforce)constraints. Main objective is the minimization of net recycling and logisticscosts offset by the profit earned by recovered material sales, and secondobjective is the maximization of hazardous materials recovery. Collection ofused products from the specified regions is decided and the required machine-hours, inventory and workforce decisions are made. Besides, both weight-based and unit-based WEEE recovery targets are separately considered, as aunique aspect. A sensitivity analysis is conducted with various scrap prices tounderstand operations planning in changing conditions. Results show thatweight-based targets enhance recovery amounts.