متن اصلی - انگلیسی - Supermarkets are a perilous business. They must...

Supermarkets are a perilous business. They must stock thousands of products in scores of brands and sizes to sell at painfully small markups. Keeping close track of them all, and maintaining inventories neither too large nor too small is critical. Yet for most of this century, as stores got bigger and the profusion on the shelves multiplied, the only way to find out what was on hand was by shutting the place down and counting every can, bag, and parcel.