By Karen E. Thuermer Mention the words “Big Shippers” and mammoth big box retailers Wal-Mart, Home Depot, Lowe’s, Best Buys, Kohl’s, Sears and others come to mind. Not only are these companies behemoth importers, behind each is a massive supply chain structure unique to each organization’s business model. Major Shipping Customer Take Home Depot, for example. The company is known for being the largest home improvement specialty retailer in the world. It has more than 2,200 retail stores in the United States (including Puerto Rico, the U.S. Virgin Islands, and Guam), Canada, Mexico and China. According to Eric Scholar, director of International Logistics for Home Depot, in 2010 the retailer saw 1.3 billion transactions, realized $68 billion in revenue, and held $10.6 billion in inventory. (Lowes realized $48.815 billion in its Fiscal Year 2010, and held $8.249 million in inventory; $8.321 million in 2011.) Home Depot buys product from suppliers in 48 countries, with 75 percent of its volume coming from China. Most significant, Home Depot is the third largest importer in the United States that buys container shipping services. “Ninety percent of those imports either enter through the Ports of Los Angeles/Long Beach, Seattle/Tacoma, Savannah, or New York/New Jersey,” Scholar commented at the Georgia Logistics Summit in Atlanta last year. The retailer, like other “Big Shippers”, uses a selection of seaports to protect its supply chain from disruptions. Even further, Scholar added, Home Depot will use around some 10 different seaports over the course of a year, depending on shipment needs. Roughly one-third of Home Depot’s shipments are shipped by ocean carriers transiting the Panama Canal. The rest come by slow steaming ocean vessels through the Suez Canal. Unlike most big retail shippers that need to stock their stores in time for the holiday season, Home Depot’s products are generally counter cyclical. Consequently, Home Depot ships items, such as patio furniture, air conditions, grills and fans primarily in January, February and March when many retail importer shipments have slacked off. As a result, Home Depot is attractive to steamship lines that want to fill their ships when the volumes of other retail goods have slowed down. It’s a win-win. Home Depot gets a cheaper rate and the steamship lines get to fill some of their ships. Like many Big Shippers, the company uses steamship services as a major component of its supply chain due to the fact it is the cheapest transport mode available. To organize the shipments arriving via steamship line, Home Depot has also established 15 distribution centers (DCs), strategically placed around the country. These are utilized to stock imported product. Most are located in close proximity to seaports. According to Scholar, Home Depot’s import warehouses range in size from 600,000 to 1.6 million square feet. Fanning out from such import warehouses, the company utilizes 60 other DCs for the restocking of stores around the country. “A key factor is to decide how much to order and know how long it will take to get here,” Scholar said. “Holding inventory and running these operations is expensive, and the more square footage you need, the more expensive it gets.” Consequently, Home Depot’s goal is to hold the least amount of inventory while satisfying customer needs. That’s a tough objective, however, given that seaports and steamship lines do not always offer supply chain visibility. Knowing where shipments are at all times can be a problem. “Visibility, especially at the seaports, is a struggle for shippers,” Scholar commented. “We may know where our shipment is on the vessel, but seaports are usually a black hole.” That’s because most seaports consider the steamship line, not the shipper, their customer. They may keep track of containers, but provide little information about the shipments themselves. “One exception is the Port of Savannah,” he said. “They know turn time and visibili