Chapman left Montgomery Ward in 1936 to open his own design office, Dave Chapman Inc., hiring William Goldsmith, Kim Yamasaki, and Paul Specht who later become partners of his firm, renamed in 1970 as Goldsmith Yamasaki Specht Inc. The firm worked during the WW II to re-adapt companies to peacetime production, and major clients included Parker Pen Company, International Harvester, Brunswick-Balke-Collender, and Scovill Manufacturing Company.
Chapman was president of the Society of Industrial Designers in 1950, and in 1954 organized a subsidiary company, Design Research, Inc., to provide long-range planning for clients. In 1955, he returned to Montgomery Ward to re-organize the Bureau of Design, which was headed by Frederick W. Priess. The Bureau lasted until 1976.
After Chapman's retirement in 1970, the surviving partners of Goldsmith, Yamasaki and Specht continued the firm successfully for over 25 years more, producing outstanding designs and retaining national visibility.
In 1996, First Design, a design firm in Kansas City , KS, purchased GYS, Inc, which had survived with Paul Specht as the only remaining partner. A partner of First Design, David McCormick, became president of GYS, and retained the Chicago office until 1999, when it was sold to Sundberg-Ferar.