Kabakulak, BanuAğralı, SemraTaşkın, Z. CanerPamuk, Bahadır2022-01-062022-01-062021Pamuk, B., Agralı, S., & Kabakulak, B. (28 Dec 2021). A Lot-Sizing Problem in Deliberated and Controlled Co-Production Systems.IISE Transactions. pp. 1-47. https://doi.org/10.1080/24725854.2021.20222502472-58542472-5862https://hdl.handle.net/20.500.11779/1728https://doi.org/10.1080/24725854.2021.2022250We consider an uncapacitated lot sizing problem in co-production systems, in which it is possible to produce multiple items simultaneously in a single production run. Each product has a deterministic demand to be satisfied on time. The decision is to choose which items to co-produce and the amount of production throughout a predetermined planning horizon. We show that the lot sizing problem with co-production is strongly NP-Hard. Then, we develop various mixed-integer linear programming (MILP) formulation of the problem and show that LP relaxations of all MILPs are equal. We develop a separation algorithm based on a set of valid inequalities, lower bounds based on a dynamic lot-sizing relaxation of our problem and a constructive heuristic that is used to obtain an initial solution for the solver, which form the basis of our proposed Branch & Cut algorithm for the problem. We test our models and algorithms on different data sets and provide the results.eninfo:eu-repo/semantics/openAccessLot-sizingMilpCo-productionBranch & cutArticle10.1080/24725854.2021.20222502-s2.0-85124411078