This paper describes a holistic methodology for business process reengineering. The methodology provides a standard flow model for reengineering, figure models which visualize the interactions in the business process to find hidden problems, and algorithms to evaluate and predict the quantitative results. Many conventional ideas based on thinking process are extended and integrated in the presented method. They include the theory of constraints, the unified modeling language, the design structure matrix, and a business process simulation technique. The methodology is currently validated for a number of different examples such as manufacturing preparation processes and car software implementation.