A Note on “An Efficient Zero‐One Formulation of the Multilevel Lot‐Sizing Problem”
指出McKnew等人提出的多层级批量问题零一整数规划模型中的约束矩阵并非全幺模，因此其线性松弛解不总是整数解。
ABSTRACT In a recent paper, McKnew, Saydam, and Coleman [3] presented a novel zero‐one integer programming formulation of the multilevel dynamic, deterministic lot‐sizing problem in assembly systems. They stated that “the relaxed linear programming solution to this formulation will always be integer’ [3, p. 280] since the constraint matrix is totally unimodular. In this note, we point out that the constraint matrix is not totally unimodular and therefore the authors’claim that a linear relaxation of the zero‐one integer formulation always yields an integer solution is not true.