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A Schedule-Based Formulation
fortheCyclic Inventory Routing Problem
Zhe Liang, Rujing Liu, and Wanpracha Art Chaovalitwongse
ABSTRACT In this chapter, we study a cyclic inventory routing problem
(CIRP). The traditional exact methods for the inventory routing problem
(IRP) use an arc-based formulation (also known as two-index ow formula-
tion), in which a variable represents a possible vehicle ow between a pair
of customers. In this research, we propose a schedule-based model (SBM), in
which a variable represents a possible one-day schedule for any vehicle. This
model can be considered a Dantzig–Wolfe decomposition of the arc-based
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