This book constitutes the refereed proceedings of the 9th International Conference on Industrial Applications of Holonic and Multi-Agent Systems, HoloMAS 2019, held in Linz, Austria, in August 2019. The 14 full papers presented were carefully reviewed and selected from 15 submissions, and 2 invited papers were also included.

IEC 61499 and the Promise of Holonic Systems.- Engineering and Validating Cyber-Physical Energy Systems: Needs, Status Quo, and Research Trends.- A Intelligent Multi-Agent Platform for Designing Digital Ecosystems.- Contribution to the theory of uncertain systems alliances.- The Framework for Designing Autonomous Cyber-Physical Multi-Agent Systems for Adaptive Resource Management.- Plan Executor MES: Manufacturing Execution System Combined with a Planner for Industry 4.0 Production Systems.- Multi-agent supply planning methods allowing the real-time performance of the supply network management systems.- Operationalization of a Machine Learning and Fuzzy Inference-Based Defect Prediction Case Study in a Holonic Manufacturing System.- Cloud-based Digital Twin for Industrial Robotics.- Semi-automatic Tool for Ontology Learning Tasks.- Agent-based Approach for Decentralized Data Analysis in Industrial Cyber-Physical Systems.- Data Exchange Ontology for Interoperability Facilitation within Industrial Automation Domain.- Information Exchange and Integration within Industrial Automation Domain.- Plant Layout Optimization Using Evolutionary Algorithms.- Experimentation of Negotiation Protocols for Consensus Problems in Smart Parking Systems.- Development of resource-demand networks for Smart Cities 5.0.