The Open Scalable Production System (OSPS) is an Industry 4.0 framework for flexible and integrated production systems. It comprises the Advanced Plant Model (APM), a software framework that acts as rendezvous between Manufacturing Execution Systems (MES) and robotic solutions running in the shop floor, providing a synchronized virtual representation of the manufacturing environment (Digital Twin). Additionally, the framework implements an Industry 4.0 Production Manager, able to coordinate human operators, robots, and automation equipment in a reliable and efficient way.