NEW YORK (TheStreet ) -- Wal-Mart (WMT) is the world's largest retailer, with more than $400 billion in store revenues in 2009. Major competitors include Costco (COST), Target (TGT) and Best Buy (BBY). Wal-Mart offers consistently low prices in both its retail stores and warehouse clubs.The retailer recently launched a store remodeling initiative called "Project Impact" that is designed to boost efficiency and sales. Wal-Mart launched Project Impact in 2008 and expects to have remodeled about 32% of its stores by the end of this year. Wal-Mart has committed to remodeling 100% of its stores by the year 2014. Below we explain how the remodeling effort is impacting Wal-Mart's business.