@article{bansal_ozaltin_uzsoy_kempf_2022, title={Coordination of manufacturing and engineering activities during product transitions}, volume={4}, ISSN={["1520-6750"]}, DOI={10.1002/nav.22056}, abstractNote={AbstractProduct transitions involve the replacement of products currently being produced and distributed by a firm with new products throughout the firm's supply chain. In high technology industries effective management of product transitions is crucial to long‐term success, and involves the coordination of multiple product development units and a manufacturing unit by a product division serving a particular market. Since the different units are organizationally autonomous, and the product division does not have access to their detailed technological constraints and internal operating policies, a decentralized solution is required. We develop a price‐based coordination framework using the subadditive dual of a mixed‐integer linear program that seeks to maximize the number of units whose proposed plans are included in the final solution. The proposed approach yields superior solutions to a linear‐programming‐based branch‐and‐price approach within the same computing budget. We discuss the broader applicability of this integer column generation approach, and suggest directions for future work.}, journal={NAVAL RESEARCH LOGISTICS}, author={Bansal, Ankit and Ozaltin, Osman Y. and Uzsoy, Reha and Kempf, Karl G.}, year={2022}, month={Apr} }
 @article{bansal_uzsoy_2021, title={Constraint violation reduction search for 0-1 mixed integer linear programming problems}, volume={53}, ISSN={["1029-0273"]}, DOI={10.1080/0305215X.2020.1742710}, abstractNote={This article presents Constraint Violation Reduction Search (CVRS), a primal heuristic for 0–1 Mixed Integer Linear Programming (MILP) problems. CVRS constructs a series of MILP subproblems by adding artificial variables representing the amount by which each constraint is violated and minimizing their sum in the objective function. A cutoff constraint added to each subproblem ensures that the objective function value of the original MILP problem improves at each iteration. If no integer feasible solution to the MILP subproblem can be found, a neighbourhood search is used to repair the infeasibility. CVRS is tested on 99 hard instances of resource constrained project scheduling, Mixed Integer Programming Library (MIPLIB) and capacitated warehouse location, and its performance is compared to a recent neighbourhood search based primal heuristic for MILP and the CPLEX MILP solver with promising results.}, number={4}, journal={ENGINEERING OPTIMIZATION}, author={Bansal, Ankit and Uzsoy, Reha}, year={2021}, month={Apr}, pages={609–626} }