The Amazon-owned supermarket chain — whose 510 stores employ 95,000 nationwide — scores each of its stores on a number of factors, including employee “‘loyalty,’ turnover, and racial diversity” according to Business Insider, which cited internal documents and five insiders with information on the program.

Whole Foods factors in how close each supermarket is to a union office, as well as the percentage of families under the poverty line who live near a given store. The supermarket also tracks the number of “tipline” calls to human resources, as well as complaints filed with the Occupational Safety and Health Administration and the National Labor Relations Board.

“Stores at higher risk of unionizing have lower diversity and lower employee compensation, as well as higher total store sales and higher rates of workers’ compensation claims,” according to documents cited by the report.

The heat map — which is “peppered with red spots to indicate high-risk Whole Foods stores,” according to the article — includes a statement which explicitly states that it “designed to identify stores at risk of unionization.”

“This early identification enables resources to be funneled to the highest need locations, with the goal of mitigating risk by addressing challenges early before they become problematic,” the statement reads.

Whole Foods did not say what the “resources” include, according to Business Insider, but said in a statement that an “overwhelming majority” of its workers prefer a “direct relationship” with management over having a union.

“At Whole Foods Market, we’re committed to treating all of our Team Members fairly, creating a safe, inclusive, and empowering working environment, and providing our Team Members with career advancement opportunities, great benefits, and competitive compensation, including an industry-leading starting minimum wage of $15/hour.”