CLEVELAND, Ohio — The opportunities offered by Cleveland schools’ reform agenda — and the obstacles to its success — took center stage Thursday as students returned from summer break.

Chief Executive Officer Eugene Sanders toured five buildings, listening to talk of initiatives such as small, specialized academies within high schools. He also got a reminder of challenges facing his academic “transformation plan,” watching as students filed into Collinwood High School 15 minutes late.

“You’d think there’d be a little more urgency on the first day,” said Sanders, who has long lamented the widespread tardiness. “We’ve got to work with parents on that.”

Hopes ride on programs like New Tech Network, an innovative project-based academy that shares Garrett Morgan School of Science on the West Side. Principal Erin Frew outlined courses such as “bioart,” which integrates science with illustration and other artistic twists.