The descriptive approaches, like case study, interview, survey, observation and document analysis, widely used by the lean construction community to investigate managerial problems in the construction industry, typically provide explanations of problems and not solutions to them, leaving a gap between theory and practice. Two prescriptive approaches-design science research and action research-are therefore recommended. Design science research and action research offer alternative approaches for studying, understanding and solving practical problems and testing innovative solutions in design and construction management, for bridging the gap between theory and practice and for making academic research more relevant to practice. They can be used to develop and/or test solutions to managerial problems in the construction industry and generate new knowledge and/or theory. The purpose of this paper is to describe design science research and action research and discuss three cases of lean construction research in which these approaches were used effectively.