A Heuristic Algorithm for the Capacitated Multiple Supplier Inventory Grouping Problem

This paper presents and solves a model for the multiple supplier inventory grouping problem, which involves the minimization of logistics costs for a firm that has multiple suppliers with capacity limitations. The costs included in the model are purchasing, transportation, ordering, and inventory holding, while the firm's objective is to determine the optimal flows and groups of commodities from each supplier. We present an algorithm, which combines subgradient optimization and a primal heuristic, to quickly solve the multiple supplier inventory grouping problem. Our algorithm is tested extensively on problems of various sizes and structures, and its performance is compared to that of OSL, a state-of-the-art integer programming code. The computational results indicate that our approach is extremely efficient for solving the multiple supplier inventory grouping problem.     

An Approximate Solution to Deterministic Kanban Systems

This paper presents a simple heuristic for computing the number of kanbans in a kanban system. The production systems under consideration have a multistage, uncapacitated, assembly tree structure, with every stage producing only one item at a time. The experimental results show that this method generates very good solutions. In more realistic problems where the master production schedule incorporates a smoothed demand, the solution found under the proposed method is identical to that of the linear programming approximation. This simple heuristic can be used in the real world to quickly determine the number of kanbans for daily just-in-time operations.     

中国棉花生产波动的实证分析

运用内部传导与外部冲击模型对我国棉花产量波动的形成原因进行了实证分析 ,结果表明 ,政策和自然灾害等外部冲击对棉花生产波动的影响较大 ,而在影响我国棉花产量波动的内部因素中 ,种植面积的波动是最主要的因素。