Eiji Toyoda, then in his 20s, started on the factory floor before being promoted to production planning and director. From the outset, he was given broad freedom to pursue interests ranging from fixing cars to helping establish the company headquarters in Toyota City. He became a director in 1945.
Toyota and Ford held discussions on jointly making cars in the United States, but they were cut off after the Japanese attack on Pearl Harbor in 1941. Talks resumed after World War II but did not lead anywhere.
In 1950, during its occupation of Japan, the U.S. Army sent Mr. Toyoda to Dearborn, Mich., to learn about mass production from Ford. The United States wanted Toyota to build trucks for its troops in Korea.
“We were producing 40 cars a day,” he later recalled. “Ford was making 8,000 units, a 200-times difference.”
But Mr. Toyoda concluded that Ford was barely ahead of the much-smaller Toyota in terms of technology. Back in Japan, he concentrated on making cars in small batches at maximum efficiency. He began using IBM machines to cut production costs, according to Kazuo Wada, professor of economics at the University of Tokyo and author of “A Fable on Manufacturing: Ford to Toyota.”
Building on the work of his cousin, Mr. Toyoda developed what became known as the Toyota Production System, which aimed to eliminate excess inventory of parts and other waste. The manufacturing system became so successful it was eventually adopted by other carmakers and by manufacturers outside the automotive industry.
He had four children with his wife, the former Kazuko Takahashi. Survivors include his eldest son, Kanshiro, according to Toyota.
Washington Post staff writer Adam Bernstein and Laurence Arnold and Masatsugu Horie, both of Bloomberg News, contributed to this report.