Modular production concepts enable flexible process plants composed of standardized process equipment assemblies (PEAs). However, the practical implementation of modular plants across the entire engineering lifecycle, including planning, approval and operation, remains challenging. Within the ENPRO REUNION project, semantic PEA datasheets (SPEADs) were developed to enable manufacturer-independent and machine-readable module descriptions. The approach was validated through the commissioning of a modular pilot plant integrating modules from different manufacturers and through the development of a modular crystallization unit. In addition, energy monitoring via digital twins and a knowledge-graph-based hazard and operability study (HAZOP) analysis were implemented. The results demonstrate key technological building blocks for modular production while highlighting remaining challenges regarding semantic integration and regulatory approval.