Many companies use strategic alliances, partnerships, and long-term contracts to create relationships with other companies in the supply chains for the products that they manufacture or sell. In many cases, companies are able to reduce costs by developing close relationships with a few suppliers rather than negotiating with a large number of suppliers each time they need to buy materials or supplies. When companies integrate their supply management and logistics activities across multiple participants in a particular product's supply chain, the job of managing that integration is called supply chain management. The ultimate goal of supply chain management is to achieve a higher-quality or lower-cost product at the end of the chain.
Supply chain management is about opting business processes and business value in every corner of the extended enterprise-from your supplier's supplier to your customer's customer. It is the strategic approach that unites all steps in the business cycle from initial product design and the procurement(采购) of raw materials, through production, shipping distribution, and warehousing until a finished product is delivered to a customer.

What do many companies use to create relationships with other companies in the supply chains?