Gearing up for a trip to Europe this summer? Experts say to be prepared for potential disruptions as countries iron out wrinkles of the European Union's so-called  Entry/Exit System , a new border management process that requires travelers to submit biometric data when they arrive in certain locations. "The goal is for people to be able to move through immigration without needing to stop and have their passport stamped," Julian Kheel, CEO and founder of Points Path, a flight awards search