Analytical Solution of Safety Stock Determination in Case of Uncertain Unimodal Lead-Time Demand

Gerrit Karel Janssens, Lotte Verdonck, Katrien Ramaekers

Abstract


As companies state that a delivery service is important to their customers, an out-of-stock is considered harmful and therefore they keep safety stock in case of uncertain demand. For decision making on the level of safety stock a complete formulation of the distributional form of the demand during lead time is required. In practice, this information may not be available. In such a case, only partial information on the distribution might be available, such as the range, the mode, the mean or the variance. Given a value for a service performance measure, the decision maker, in this case, is not confronted with a single value for the safety stock but rather with an interval. The present research shows how upper and lower bounds of the safety stock are obtained in an analytical way, given a pre-specified service level using a service performance measure, called ‘expected number of units short’. The technique is also illustrated and compared within the framework of the research.


Keywords:

Inventory management; uncertain demand; safety stock; unimodal distributions

Full Text:

PDF

References


E. A. Silver, D. F. Pyke and R. Peterson, Inventory management and production planning and scheduling (third edition). New York, NY, USA: Wiley and Sons, 1998.

E. Naddor, “Note–Sensitivity to distributions in Inventory Systems”, Management Science, vol. 24, no. 16, pp. 1769–1772, 1978. https://doi.org/10.1287/mnsc.24.16.1769

E. Bartezzaghi, R. Verganti, and G. Zotteri, “Measuring the impact of asymmetric demand distributions on inventories”, International Journal of Production Economics, vol. 60–61, pp. 395–404, 1999. https://doi.org/10.1016/S0925-5273(98)00193-5

H.-S. Lau and A. Zaki, “The sensitivity of inventory decisions to the shape of lead time-demand distribution”, AIIE Transactions, vol. 14, no. 4, pp. 265–271, 1982. https://doi.org/10.1080/05695558208975239

A. Käki, A. Salo, and S. Talluri, “Impact of the shape of demand distribution in decision models for operations management”, Computers in Industry, vol. 64, no. 7, pp. 765–775, 2013. https://doi.org/10.1016/j.compind.2013.04.010

G. K. Janssens and K. Ramaekers, “A linear programming formulation for an inventory management decision problem with a service constraint”, Expert Systems with Application, vol. 38, no. 7, pp. 7929–7934, 2011. https://doi.org/10.1016/j.eswa.2010.12.009

H. Scarf, “A min-max solution of an inventory problem.” In K.J Arrow, S. Karlin and H. Scarf (Eds.) Studies in the mathematical methods of inventory and production. Redwood City, CA, Stanford University Press, pp. 201–209, 1958.

B. Heijnen and M. J. Goovaerts, “Best upper bounds on risks altered by deductibles under incomplete information”, Scandinavian Actuarial Journal, vol. 1989, no. 1, pp. 23–46, 1989. https://doi.org/10.1080/03461238.1989.10413853

K. Janssen, J. Haezendonck and M. J. Goovaerts, “Upper bounds on stop-loss premiums in case of known moments up to the fourth order”, Insurance Mathematics and Economics, vol. 5, no. 4, pp. 315–334, 1986. https://doi.org/10.1016/0167-6687(86)90027-2

D. G. Malcolm, J. H. Roseboom, C. E. Clark and W. Fazar, “Application of a technique for research and development program evaluation”, Operations Research, vol. 7, no. 5, pp. 646–669, 1959. https://doi.org/10.1287/opre.7.5.646

M. J. Goovaerts, F. de Vylder and J. Haezendonck, Insurance Premiums. Amsterdam: North-Holland, 1984.

G. K. Janssens and K. M. Ramaekers, “On the use of bounds for the stop-loss premium for an inventory decision problem”, Journal of Interdisciplinary Mathematics, vol. 11, no. 1, pp. 115–126, 2008. https://doi.org/10.1080/09720502.2008.10700546




DOI: 10.7250/itms-2018-0012

Refbacks

  • There are currently no refbacks.


Copyright (c) 2018 Gerrit K. Janssens, Lotte Verdonck, Katrien Ramaekers

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.