This book constitutes the thoroughly refereed scientific proceedings of the 4th International Conference on Subject-Oriented Business Process Management, S-BPM ONE 2012, held in Vienna, Austria, in April 2012.The 12 papers were carefully reviewed and selected from 36 submissions and are completed by one invited keynote paper and a summary of the tutorial on subject-oriented business process management. S-BPM as a discipline is characterized by a seamless approach toward the analysis, modeling, implementation, execution, and maintenance of business processes, with an explicit stakeholder focus. This year's contributions address all life-cycle activities, in particular analyzing business objectives, subject behavior design and integration, and automating complex work procedures.