Keywords: Closed-loop supply chains

are for many companies, given the high number of factors involved and their intricate interactions. n issue many cases, the reverse chain depends on the existing forward chain. This is especially true if products are recovered from original equipment manufacturers (Fleischmann et al., 2001). Several ques-tions must be answered in order to deal with this supply chain ex-tended problem such as: Should reverse flows be included in the existing distribution ones? Or should they be separated? If sepa-decisions that hold from more than 3 to 5 years are said to be stra-tegic. On the other hand, if 1 hour, 1 month or one trimester is the time horizon, these decisions are taken as operational. All decisions with an intermediate duration are classified as tactical (Vidal and Goetschalckx, 1997). Note that these time units are merely an indi-cation and may differ from company to company. To achieve a global and integrated system, strategic decisions should be taken in close relation with the more tactical issues (Goetschalckx et al., 2002b). Integrated decisions with differen