activities and best practices can save time in the early phases of business system development. To help developers share know-how and best practices, we have developed a methodology and a tool for business process modeling and have applied it to a system development project. Furthermore, we have developed processtemplate development techniques to realize granularityunification of business processes so that business process models can be reused, and have clarified the practical divisions of process models and the design issues concerning each division. These techniques enable the preparation of reuseoriented business process templates before the business process modeling activity. In this paper, we describe the methodology and tool, including a meta-model and notations we have constructed for business modeling. We then consider the effectiveness of the methodology and tool: in an actual development project, the tool and business process templates decreased development time by 46% or more.