Formalizing UML Sequence Diagrams Using SBC-SD Process Algebra

A UML sequence diagram is widely used for system design, but it lacks formal semantics, leading to ambiguity and misinterpretation. Formalizing UML sequence diagrams provides unambiguous semantics, ensuring consistency across different teams and tools. Standard UML sequence diagrams struggle with concurrency, requiring workarounds like parallel states. Process-oriented elements in SBC-SD (Structure-Behavior Coalescence for Sequence Diagrams) naturally model concurrency using process composition (e.g., parallel execution). State-oriented models lack modularity; they require complex diagrams for reusable components. Process-oriented models naturally allow component-based design using encapsulated behaviors. SBC-SD enables hierarchical composition, where state transitions and process executions coexist seamlessly. Overall, by combining state-oriented and process-oriented modeling, SBC-SD provides a rigorous, concurrent, and composable basis for UML sequence diagrams. This integration eliminates ambiguity through formal execution semantics, enables natural concurrency without complex workarounds, and improves modularity for large-scale system design. View Less