Savvy companies have wooed their employees with extras like quality meals and transportation to work. But Man Wah and other Chinese companies answer to bosses in China, who are conditioned toward thrift while thinking of workers as easily replaceable.

Finding local suppliers is also a challenge. Under the terms of the North American trade agreement, manufacturers must employ minimum percentages of parts and raw materials from within the region to qualify for duty-free access to the other countries in the bloc.

Three years ago, Lenovo, the Chinese computer maker, opened a factory in Monterrey dedicated to making servers, the boxes that hold data for cloud computing.

Until last year, Lenovo flew in one crucial component — so-called motherboards — from a factory in China. But as international shipping troubles intensified, the company switched to a supplier in the Mexican city of Guadalajara.

Lenovo also stopped importing packaging materials from China, instead buying them in Mexico.

But Lenovo continues to import many key components from China, from memory devices to specialized cables.

“There’s no supply chain for these things in Mexico,” said Leandro Sardela, the company’s Western operations director.

At least, not yet.