A business process architecture (BPA) model depicts business processes in an organization and their relations. An artifact for generating BPA models is proposed as the outcome of a design science research project. The proposed artifact consists of a method (i.e., a set of concepts, a proposed notation, and a detailed procedure), which is termed the domain-based BPA (dBPA) method due to using domain models as a starting point. The dBPA method tackles issues of currently available approaches: lack of structured inputs, limited consideration of process relations types, and restricted use of industry-standard modeling languages. The paper formalizes the dBPA method and illustrates its application in the manufacturing industry. Evaluation of the dBPA method revealed that practitioners perceived it as useful to achieve its goal with the benefits of being objective and clear and allowing to create complete and understandable BPA models that enable the integration of processes and the software that automates them.