Abstract
The Eclipse Arrowhead Framework provides a service-oriented architecture for distributed industrial automation through service discovery, authorization, orchestration, and quality-of-service-aware service selection. While the framework formally defines the execution of individual service interactions, it does not provide a mathematical semantics for coordinating multiple dependent service invocations into executable workflows. This paper presents a compact mathematical execution model for Arrowhead workflow choreography. Rather than introducing a new orchestration mechanism, the proposed model extends the Arrowhead Framework conservatively by treating workflow execution as the repeated compilation of workflow steps into ordinary Arrowhead service requests. The model introduces formal representations of workflow recipes and workflow sessions, together with a compact execution model that maps executable workflow steps to ordinary Arrowhead orchestration requests and service invocations. A worked example demonstrates how the notation can be instantiated for a generic setting, whereas another example shows a concrete temperature-control workflow, and a third example a shared-tool delivery workflow in a forklift assembly plant. The resulting formalization preserves the service-oriented semantics of the Arrowhead Framework while providing a mathematically precise model for workflow execution, including measurement workflows that coordinate sensing, validation and actuation services, in dynamic industrial environments.