Automakers are grappling with their supply of parts after resuming operations on May 18, 2020, with workers complaining that assemblers cannot do their jobs when they do not have 100% of the parts.

Ford's Dearborn Truck plant had to stop production early when it ran out of the seats it needed to build F-150 pickups on Thursday, May 28, and resumed work Monday. General Motors (GM) had planned to add shifts at US plans last week, but it had to delay that move because it lacked sufficient parts. When it finally received enough supply on Monday GM added a second shift at three SUV plants in the United States and Canada, and went from one to three shifts at three plants building pickup trucks, Chris Isidore wrote for CNN Business late on June 2, 2020.

"The situation has been so fluid," said GM spokesman Jim Cain. Cain said the supplier plants had to demonstrate to GM -- and in the case of Mexican plants, to government authorities -- that they had safety procedures in place to protect people returning to work. GM, Ford and Fiat Chrysler suspended operations in response to the pandemic in mid-March. They all resumed work at their plants the week of May 18.

About two thirds of the auto industry's 1 million US employees work at a supplier plant rather an assembly line, engine or stamping plant of one of the major manufacturers, according to the Labor Department. Many more work at suppliers outside the country. Keeping all the workers on the supply chain healthy will be very difficult, said Kristin Dziczek, vice president for research for the Center for Automotive Research, a Michigan think tank. "It's a very big concern," she said. Each auto plant has hundreds of suppliers, which makes the challenges of keeping the entire supply chain operating particularly difficult. The plants are designed to have parts delivered with little time to spare -- known as just-in-time delivery.