bumpyは「こぶの」ということですが、そこからget ［be］ off to a bumpy startというイディオムが生まれました。「多難な幕開け」という日本語に近いと思います。（UG）
Bumpy Start for Teacher Evaluation Program in New York Schools
Over the 24 years Lily Din Woo has been the principal of Public School 130 in Lower Manhattan, her typical day changed very little: sick or misbehaving students, budgets, curriculum woes and meetings with parents, many of whom do not speak English.
This year, however, she and the assistant principal are spending parts of each day darting in and out of classrooms, clipboards and iPads in hand, as they go over checklists for good teaching. Is the lesson clear? Is the classroom organized?