Many articles and business cases have been written about Wal-Mart. Most customers are probably familiar with the store and the overall concepts, but a considerable amount of work takes place to manage the large inventory, suppliers, pricing, customers, and employ-ees. Wal-Mart has been a leader in using information technology to reduce costs. A huge part of succeeding in retailing is to provide the right products in the stores at the right price, when customers want to buy them. To succeed, Wal-Mart needs to forecast demand for every product in every store. Each product can have multiple variations—such as size or color. Individual items are commonly identified with an SKU number (stock-keeping unit), pronounced “skew.” Any Wal-Mart store has tens of thousands of SKUs. Of course, all of this data needs to be tracked by IT. Wal-Mart also can track personal purchases—based on credit and debit cards. All of the data from every store is collected and sent to the central servers at Bentonville, Arkansas.