Contents I. Introduction
The logistics management is the third benefit source of an enterprise as a new research topic following the production and sale, which plays an important role in market competition. The purchasing logistics as a key component of an enterprise logistics system takes an important proportion. It has a significant effect on the normal production and economic benefit. In addition, it is a crucial tache of the production of an enterprise. Steel-iron industry is representative of the flow industry. The purchasing costs of raw materials, machine equipments, and spare parts hold a dominant fraction in production cost. The characteristics of steel-iron enterprise are continuity of production procedure, the dispersion of vendors and strict requirements to the quality, which lead to the purchasing problem more complex and important. After becoming a member of World Trade Organization (WTO), the steel-iron enterprises in China are challenged with the multinational corporations, which require not only the interior logistics but also the exterior logistics being optimized. In new situation, the relationship between the purchaser and vendor is changed greatly. The purchase action isn't only involved in cost control, but also affects morality and credit standing of the enterprises. The purchasing management level becomes the core competition of a large-scale steel-iron enterprise. Owing to purchasing particularity of the steel-iron, the related literatures for a steel-iron enterprise are relatively few. Unfortunately, no literature focuses on the roll purchasing problem. The roll is crucial spare part of the enterprise production, which has property of high-volume, high-cost. As result, its purchasing cost and quality affect enterprise's competition directly. In many large-scale steel-iron enterprises, the roll vendor selection and roll production management have been added to the Enterprise Resource Planning (ERP).
