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Degeneracy in inventory models
Author(s) -
Lau Amy HingLing,
Lau HonShiang,
Pyke David F.
Publication year - 2002
Publication title -
naval research logistics (nrl)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 68
eISSN - 1520-6750
pISSN - 0894-069X
DOI - 10.1002/nav.10037
Subject(s) - stockout , degeneracy (biology) , reorder point , degenerate energy levels , economic order quantity , order (exchange) , point (geometry) , computer science , operations research , mathematical economics , mathematical optimization , mathematics , econometrics , economics , business , physics , marketing , supply chain , geometry , finance , quantum mechanics , biology , bioinformatics
Abstract In order‐quantity reorder‐point formulations for inventory items where backordering is allowed, some of the more common ways to prevent excessive stockouts in an optimal solution are to impose either a cost per unit short, a cost per stockout occasion, or a target fill rate. We show that these popular formulations, both exact and approximate, can become “degenerate” even with quite plausible parameters. By degeneracy we mean any situation in which the formulation either cannot be solved, leads to nonsensical “optimal” solutions, or becomes equivalent to something substantially simpler. We explain the reasons for the degeneracies, yielding new insight into these models, and we provide practical advice for inventory managers. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 686–705, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10037