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Single-item continuous-review inventory models with random supplies

Published online by Cambridge University Press:  27 January 2025

Kurt L. Helmes*
Affiliation:
Humboldt University of Berlin
Richard H. Stockbridge*
Affiliation:
University of Wisconsin–Milwaukee
Chao Zhu*
Affiliation:
University of Wisconsin–Milwaukee
*
*Postal address: Institute for Operations Research, Humboldt University of Berlin, Spandauer Str. 1, 10178, Berlin, Germany. Email address: [email protected]
**Postal address: Department of Mathematical Sciences, University of Wisconsin–Milwaukee, Milwaukee, WI 53201, USA.
**Postal address: Department of Mathematical Sciences, University of Wisconsin–Milwaukee, Milwaukee, WI 53201, USA.

Abstract

This paper analyzes single-item continuous-review inventory models with random supplies in which the inventory dynamic between orders is described by a diffusion process, and a long-term average cost criterion is used to evaluate decisions. The models in this class have general drift and diffusion coefficients and boundary points that are consistent with the notion that demand should tend to reduce the inventory level. Random yield is described by a (probability) transition function which depends on the inventory on hand and the nominal amount ordered; it is assumed to be a distribution with support in the interval determined by the order-from and the nominal order-to locations of the stock level. Using weak convergence arguments involving average expected occupation and ordering measures, conditions are given for the optimality of an (s, S) ordering policy in the general class of policies with finite expected cost. The characterization of the cost of an (s, S) policy as a function of two variables naturally leads to a nonlinear optimization problem over the stock levels s and S, and the existence of an optimizing pair $(s^*,S^*)$ is established under weak conditions. Thus, optimal policies of inventory models with random supplies can (easily) be numerically computed. The range of applicability of the optimality result is illustrated on several inventory models with random yields.

Type
Original Article
Copyright
© The Author(s), 2025. Published by Cambridge University Press on behalf of Applied Probability Trust

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References

Bar-Lev, S. K., Parlar, M. and Perry, D. (1994). On the EOQ model with inventory-level-dependent demand rate and random yield. Operat. Res. Lett. 16, 167176.CrossRefGoogle Scholar
Bensoussan, A. (2011). Dynamic Programming and Inventory Control. IOS Press, Amsterdam.Google Scholar
Bogachev, V. I. (2007). Measure Theory, Vol. 2. Springer, Berlin.CrossRefGoogle Scholar
Chen, H., Wu, O. Q. and Yao, D. D. (2010). On the benefit of inventory-based dynamic pricing strategies. Prod. Operat. Manag. 19, 249260.CrossRefGoogle Scholar
Ethier, S. N. and Kurtz, T. G. (1986). Markov Processes: Characterization and Convergence. John Wiley, New York.CrossRefGoogle Scholar
Federgruen, A. and Zipkin, P. (1986). An inventory model with limited production capacity and uncertain demands I. The average-cost criterion. Math. Operat. Res. 11, 193207.Google Scholar
Helland, I. (1996). One-dimensional diffusion processes and their boundaries. Tech. Rep., University of Oslo. Available at https://core.ac.uk/download/pdf/30815803.pdf.Google Scholar
Helmes, K. L., Stockbridge, R. H. and Zhu, C. (2017). Continuous inventory models of diffusion type: long-term average cost criterion. Ann. Appl. Prob. 27, 18311885.CrossRefGoogle Scholar
Helmes, K. L., Stockbridge, R. H. and Zhu, C. (2018). A weak convergence approach to inventory control using a long-term average criterion. Adv. Appl. Prob. 50, 10321074.CrossRefGoogle Scholar
Helmes, K. L., Stockbridge, R. H. and Zhu, C. (2024). On the modelling of uncertain impulse control for continuous Markov processes. SIAM J. Control Optimization. 62, 699–723.CrossRefGoogle Scholar
Inderfurth, K. and Transchel, S. (2007). Note on myopic heuristics for the random yield problem. Operat. Res. 55, 11831186.CrossRefGoogle Scholar
Inderfurth, K. and Vogelsang, S. (2013). Periodic review inventory systems with fixed order cost and uniform random yield. Europ. J. Operat. Res. 224, 293301.CrossRefGoogle Scholar
Karlin, S. and Taylor, H. M. (1981). A Second Course in Stochastic Processes. Academic Press, New York.Google Scholar
Korn, R. (1997). Optimal impulse control when control actions have random consequences. Math. Operat. Res. 22, 639667.CrossRefGoogle Scholar
Lungu, E. and Øksendal, B. (1997). Optimal harvesting from a population in a stochastic crowded environment. Math. Biosci. 145, 4775.CrossRefGoogle Scholar
Sato, K., Yagi, K. and Shimakazi, M. (2018). A stochastic inventory model for a random yield supply chain with wholesale-price and shortage penalty contracts. Asia-Pacific J. Operat. Res. 35, article no. 1850040.CrossRefGoogle Scholar
Serfozo, R. (1982). Convergence of Lebesgue integrals with varying measures. Sankhya A 44, 380–402.Google Scholar
Sigman, K. and Wolff, R. W. (1993). A review of regenerative processes. SIAM Rev. 35, 269288.CrossRefGoogle Scholar
Song, Y. and Wang, Y. (2017). Periodic review inventory systems with fixed order cost and uniform random yield. Europ. J. Operat. Res. 257, 106117.CrossRefGoogle Scholar
Tinani, K. S. and Kandpal, D. H. (2017). Literature review on supply uncertainty problems: yield uncertainty and supply disruption. J. Indian Soc. Prob. Statist. 18, 89109.CrossRefGoogle Scholar
Yano, C. A. and Lee, H. L. (1995). Lot sizing with random yields: a review. Math. Operat. Res. 43, 311334.CrossRefGoogle Scholar
Yao, D., Chao, X. and Wu, J. (2015). Optimal control policy for a Brownian inventory system with concave ordering cost. J. Appl. Prob. 52, 909925.CrossRefGoogle Scholar
Zheng, Y. S. and Federgruen, A. (1991). Finding optimal (s, S) policies is about as simple as evaluating a single policy. Operat. Res. 39, 654665.Google Scholar