@article{albey_norouzi_kempf_uzsoy_2015, title={Demand Modeling With Forecast Evolution: An Application to Production Planning}, volume={28}, ISSN={["1558-2345"]}, DOI={10.1109/tsm.2015.2453792}, abstractNote={The value of demand forecast information has been the subject of numerous studies in the inventory literature, but has had limited application in production planning. This paper integrates ideas from forecast evolution and inventory theory to plan work releases into a production facility in the face of stochastic demand. The model, which is solved on a rolling horizon basis, manages the inventory, backorder, and shortfall levels at each planning epoch using chance constraints to represent desired service levels. The evolution of demand information over time is modeled using the Martingale Model of Forecast Evolution. The model is implemented using historical data from a major semiconductor manufacturer. The value of forecast evolution is quantified using a benchmark model that does not consider forecast evolution.}, number={3}, journal={IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING}, author={Albey, Erinc and Norouzi, Amirhosein and Kempf, Karl G. and Uzsoy, Reha}, year={2015}, month={Aug}, pages={374–384} }
 @article{kang_albey_hwang_uzsoy_2014, title={The impact of lot-sizing in multiple product environments with congestion}, volume={33}, ISSN={["1878-6642"]}, DOI={10.1016/j.jmsy.2014.04.003}, abstractNote={We present a production planning model for a multiple product single machine dynamic lot-sizing problem with congestion. Using queuing models, we develop a set of functions to capture the nonlinear relationship between the output, lot sizes and available work in process inventory levels of all products in the system. We then embed these functions in a nonlinear optimization model with continuous variables, and construct an approximate solution to the original problem by rounding the resulting fractional solution. Computational experiments show that our model with congestion provides significantly better flow time and inventory performance than a benchmark model that does not consider the effects of congestion. These advantages arise from the use of multiple smaller lots in a period instead of a single large lot as suggested by conventional fixed-charge models without congestion.}, number={3}, journal={JOURNAL OF MANUFACTURING SYSTEMS}, author={Kang, Yongha and Albey, Erinc and Hwang, Sangwook and Uzsoy, Reha}, year={2014}, month={Jul}, pages={436–444} }