Abstract: Traditional theory of PDCA (Plan, Do, Check, Action) circulation is an important method of raising product quality and improving enterprise’s operation management, but also has shortcomings such as lack of creativity, lack of communication, collaboration and knowledge sharing, lack of tacit knowledge mining, and limited by the ideology of “customer is God” from total quality management (TQM). On the basis of PDCA circulation theory, we present a technology of relay chain helix (RCH) circulation, and elaborate its operation principles, steps, processes and characteristics. This technology overcomes the problems in the application of PDCA circulation theory, and also improves the system’s creativity, the quality and efficiency of continuous improvement. It was applied to the quality control for concrete construction in the third phase of Three Gorges Project, and has improved the project quality. The project was completed 9 months ahead of schedule, which is a miracle of concrete construction with no crack.

Key words: RCH circulation, PDCA, continuous improvement, Three Gorges Project