New Valid Inequalities for a Multi-echelon Multi-item Lot-Sizing Problem with Returns and Lost Sales

This work studies a multi-echelon multi-item lot-sizing problem with remanufacturing and lost sales. The is formulated as mixed-integer linear program. A new family of valid inequalities taking advantage the structure introduced used in customized branch-and-cut algorithm. provided numerical results show that proposed algorithm outperforms both generic embedded standard-alone mathematical solver previously published