Corporate travel is big - really big - business. According to a July 2017 report from the Global Business Travel Association, global business travel spend approached $1.3 trillion in 2016, and it's expected to grow steadily over the next few years. For corporate travel managers, the challenge of overseeing these massive budgets - and the myriad of vendors, contracts, invoices and human resources built into them - is exacerbated by the growing demand of travelers to make their trips convenient, stress-free and personalized to their needs. The risk of not meeting those desires is that those travelers take matters into their own hands, booking flights and accommodations independently. "What most travel managers are after is adoption of the channel - making sure they have full transparency of what is going on and where travelers are booking, and not getting it through expense reports when money is already cashed out," says Martin Biermann, vice present of product development and chief technology officer for HRS, which provides hotel sourcing, booking and management solutions for more than 3,000 businesses worldwide.