Automation systems, like power plants and industrial production plants, usually involve heterogeneous engineering domains, e.g., mechanical, electrical, and software engineering, that are required to work together to de-liver good products and services to customers. However, the heterogeneity of workflows used in different engineering domains make it hard for project man-agers to integrate and validate such workflows. We propose to add the Engi-neering Service Bus (EngSB) notion with a framework to integrate and validate heterogeneous workflows from different engineering fields and to link connec-tions between different types of signals. For evaluation, we perform a feasibility study on a signal change management of our industry partner in hydro power plant engineering domain. Major result shows that the framework can support workflow validation and improve the observability of heterogeneous workflows in distributed engineering environments.