Multi-product economic lot scheduling problem with separate production lines for manufacturing and remanufacturing

We study the economic lot scheduling problem with two production sources, manufacturing and remanufacturing, for which operations are performed on separate, dedicated lines. We develop an exact algorithm for finding the optimal common-cycle-time policy. The algorithm combines a search for the optimal cycle time with a mixed integer programming (MIP) formulation of the problem given a fixed cycle time. Using case study data from an auto part producer, we perform a sensitivity study on the effects of key problem parameters such as demand rates and return fractions. Furthermore, by comparing to results in Tang and Teunter [Tang, O., Teunter, R.H., 2006. Economic lot scheduling problem with returns. Production and Operations Management] for the situation where all operations are performed on the same line, we analyze the cost benefits of using dedicated lines.