The Factored Transportation Problem
证明当成本系数为ui×vj形式时，按特定顺序排列行列后，西北角法能给出最优解，并验证了仓库库存定位问题中一个启发式方法的优化性。
The factored transportation problem is one having cost coefficients of the form c ij = u i v j . The main result proven in this paper is that if rows are arranged according to nonincreasing u i and columns by nondecreasing v j , then the northwest corner rule provides an optimal solution. Applications to stock location in a warehouse and information storage and retrieval policies are presented. For the stock location problem, this verifies that a previously advocated heuristic is optimal.