This book constitutes the proceedings of the BPM Forum of the 19th International Conference on Business Process Management, BPM 2021, which will take place in Rome, Italy, in September 2021. The BPM Forum offers innovative research papers characterized by their high potential of stimulating interesting discussion and scientific debate, although without yet reaching the same rigor as the papers accepted for the main conference. In this sense, the BPM Forum papers are characterized by novel ideas about emergent BPM topics. The 16 papers presented in this volume were carefully reviewed and selected from a total of 123 submissions to the main conference. They cover all areas of business process management, from process definition to variability, execution, visualization, monitoring, mining, and optimization.