Ford Motor Co., which has the industry's largest U.S. hourly work force at 55,000, also is believed to have the fewest temporary workers. At the end of 2018, Ford had about 3,400 temps, representing 6 percent of its U.S. hourly work force. It has hired 3,700 other temporary workers as full-time employees under the 2015 contract.
The automakers' use of temps varies and runs higher in summer. GM has about 4,650 temps, representing 10 percent of the 46,000 people in its U.S. hourly work force, though its annual average runs closer to 7 percent. FCA has about 47,000 U.S. hourly employees, and is believed to have about the same number of temporary workers as GM or slightly more.
Art Schwartz, president of Labor and Economics Associates and a former director of labor relations at GM, said temporary workers have a long history with the Detroit 3 and the union has agreed at times to keep them on to increase union membership.
"Companies want temps for the most part for vacation replacement, startups and temporary volume spikes," Schwartz wrote in an email. "Flexibility is the key. However, it is harder to justify temps if you're laying people off."
During the last round of contract talks, FCA expanded its ability to use temporary workers from Friday through Monday to all week. Ford also has increased its use of temps. In 2015, FCA and GM used them for 5 to 10 percent of annual hours worked, vs. less than 1 percent for Ford, according to the Center for Automotive Research.
In 2015, temps at GM and Ford were paid a $2,000 bonus after ratifying the contract that year. They also received a health care plan.
Dziczek said establishing a cap on temporary workers might be reasonable and doable for the union under this round of bargaining.
She said, "They'll have to win something there if they're going to give more flexibility on temps."
Vince Bond Jr. and Michael Martinez contributed to this report.