Porter's Five Forces

• Supplier concentration
• Importance of volume to supplier
• Differentiation of inputs
• Impact of inputs on cost or differentiation
• Switch costs of firms in the industry
• Presence of substitute inputs
• Threat of forward integration
• Cost relative to total purchases in industry

You can search databases for articles in newspapers, trade/professional journals, newswires, etc. for mentions of a company's suppliers. Sometimes suppliers report their relationship or contracts with a major company. Go beyond just searching with the keywords - suppliers or supply chain. Look for mentions of  new contracts, joint ventures, partnerships, or distributors. Other keywords you might use in your search are procurement, purchasing, inventory management, outsourcing, suppliers, warehousing, logistics and operations management. Use these databases: