UPS and its union, called Teamsters, recently ended its latest negotiation session with no deal. Meanwhile, the deadline is looming. The union’s contract expires on July 31. It means nearly 350,000 UPS workers could go on strike.

The last time UPS workers went on strike was 1997, that strike lasted 15 days, and cost $850 million. 

“Pure chaos was the best it can be described,” said Jason Miller, a professor of supply chain management at Michigan State. “And we didn’t have this incredible amount of e-commerce packages.”

Back then, Amazon mostly sold books. And Target and Walmart didn’t offer online shopping. 

UPS delivers about a third of the country’s parcels. Miller said other carriers won’t be able to absorb all the volume. And nearly half of UPS’ deliveries are business to business shipments. 

“Wholesalers of professional and commercial equipment so like computers, smartphones and things like that,” Miller said.

It means production of some goods could slow, but, there is a silver lining. 

“If this has to happen this is probably as good of a time as any,” said Willy Shih, a professor of management at Harvard.

Americans haven’t been buying as much stuff. And summer is a low shipping season. But Shih said it’ll still be very disruptive.