A little more than a year ago, Southwest Airlines was having trouble with its cargo operations. Even though the average plane was using only 7% of its cargo space, at some airports there wasn't enough capacity to accommodate scheduled loads of freight, leading to bottlenecks throughout Southwest's cargo routing and handling system. At the time, employees were trying to load freight onto the first plane going in the right direction -- a seemingly reasonable strategy. But because of it, workers were spending an unnecessary amount of time moving cargo around and sometimes filling aircraft needlessly.