PARIS — On a recent weekday, while France was still under one of Europe’s tightest lockdowns, mammoth six-foot tractor tires were rolling off the assembly line at a Michelin factory in northeast France. Farther south, other Michelin plants turned out tires for ambulances and fire trucks as fast as small skeleton crews could make them.

Michelin is an early starter among global manufacturers seeking to revive business safely in the midst of the coronavirus pandemic. A gradual reopening is being tested after the outbreak temporarily shuttered plants in China, Europe and the United States, affecting 127,000 employees.

“We can’t stay confined forever,” Florent Menegaux, Michelin’s chief executive, said by telephone recently. “Just after the health crisis, we’re going to have an economic crisis looming which will have huge social consequences. We have to learn how to live with Covid-19.”