OCL in IEC 61850: from checking XML to checking engineering rules
A new mechanism for validating SCL files is emerging in the IEC 61850 engineering process — OCL (Object Constraint Language), a language for formally describing constraints and rules for the objects of the information model. The technical specification IEC TS 61850-6-3, published in 2025, defines a format for machine-processable rules that software tools can import and apply to SCL automatically. XSD only answers the question «is the XML document well-formed?», whereas many requirements of the standard concern the relationships between the objects of the model. OCL makes it possible to move from checking the formal correctness of XML to the automated checking of engineering rules that previously had to be interpreted and controlled by hand.