Application of optimization methods in the closed-loop supply chain: a literature review

An essential aspect of a closed-loop supply chain (CLSC) involves its optimization. In this context, systematizing the publications on optimization methods applied in CLSC constitutes this research's primary objective. In this sense, a comprehensive literature review was carried out on 354 papers published from January 2008 to October 2020 to find future directions involving CLSC optimization. It was found stochastic methods are the primary approach in the studies regarding CLSC optimization, being applied in 27.68% of the publications investigated, while hybrid methods appeared in 21.75%, and deterministic methods were used in 20.62%. It was verified that 49.71% of the publications were related exclusively to strategic decisions concerning organizational decision-making levels, 22.03% analyzed tactical decisions, and 13.56% studied operational aspects. Regarding the sustainability dimensions, it was found that only the economic dimension was investigated in 70.62% of the analyzed publications. The three dimensions (economic, environmental, and social) were investigated simultaneously in only 6.21% of the publications. As the main conclusion, a lack of research covering the whole spectrum of the CLSC environment was found, comprising the various levels of organization decisions and sustainability dimensions of the triple bottom line.