Process computers have a long history of use in the steel industry, where they have made a remarkable contribution to product quality and production efficiency. Moreover, process computer functions have become increasingly sophisticated and complex in response to the requirements of high-level line automation, making the improvement of software quality and productivity an essential task. Since 1987, Kawasaki Steel has actively promoted the development of techniques for the improvement of software productivity. The main software techniques developed are as follows. (1) Autonomous distributed systems An autonomous distributed system was put into practical application in the steel industry for the first time at Mizushima Works, resulting in improved software portability, which had been inadequate with process computer systems in the past. (2) Reuse of software Better efficiency was achieved in software design and production by the use of parts management practices developed for software specifications and programs on the basis of improved software portability. (3) Improved development environment A network system is essential as infrastructure for the reuse of software; a high-speed/highcapacity FDDI was introduced for this purpose. A multi-vendor development environment was constructed by linking process computer systems, workstations, and personal computers. These techniques were applied to a CGL system and to two continuous annealing line systems. The results include a reduction in software bugs and a two-fold increase in productivity. This paper presents an outline of software techniques developed by Kawasaki Steel Corporation.