This book constitutes the proceedings of two events held at the CAiSE conference and relating to the areas of enterprise, business process and information systems modeling:

The 20th International Conference on Business Process Modeling, Development and Support, BPMDS 2019, and the 24th International Conference on Evaluation and Modeling Methods for Systems Analysis and Development, EMMSAD 2019. The conferences took place in Rome, Italy, in June 2019.

The 7 full and 2 short papers accepted for BPMDS were carefully reviewed and selected from a total of 20 submissions; for EMMSAD 15 full papers were accepted from 38 submissions.

The papers were organized in topical sections named as follows:

BPMDS: large and complex business process modeling and development; execution and understandability of declarative process models; novel approaches in enterprise modeling; transformative business process modeling, development, and support.

EMMSAD: foundations of modeling and method engineering; enterprise process and capability modeling; information systems and requirements modeling; domain-specific and ontology modeling; and evaluation of modeling approaches.