Kraay began a career with Western Electric in 1946 as a manufacturing process and development engineer. He progressed to a management position and, in 1956, was awarded a Sloan Fellowship for a year of intensive study at the Sloan School of Management at MIT. At the conclusion of the program, he received an MS degree in industrial management. Kraay returned to Western Electric with increased engineering and administrative responsibilities and became general manager of the Reading plant which manufactures semiconductors. He was promoted to general manager (central region) of the service division in 1968.

In 1971, he accepted a position as executive vice president of Sandia Laboratories, a weapons laboratory operated by Western Electric for the government. In 1972, he was elected an executive officer of Western Electric and became vice president of human resources. Kraay's responsibilities shifted to vice president of purchasing and transportation in 1976 and to vice president of engineering resources in 1983, a position from which he retired in 1985.