## 5 Properties and Benefits of the Arrowhead-EP and the VCEP-Map  
In Sections 2-4, we detail the Arrowhead-EP model and the ontology for enabling the digitalised management of the life cycle of complex industrial multistakeholder use cases. This section discusses some of the notable advantages offered by the adoption of the Arrowhead-EP model and the VCEP-map in the Industry 4.0 domain. The Arrowhead-EP model complemented by the VCEP map proposed in this paper addresses the six objectives (see Section 3) that an EP should support to satisfy the needs of the life cycle management of an Industry 4.0-oriented solution. Thus, the Arrowhead-EP model, complemented by the VCEP map, is widely flexible and adaptable to support a large spectrum of heterogeneous vertical UCs, ranging from semiconductor engineering to mining, finance, construction industry, IoT, etc. The Arrowhead-EP model allows feedback that provides inputs to previous phases of the EP and introduces a specific phase focused on _Evolution_, intended to provide feedback for system bug fixes, updates, and future releases. This enables continuous engineering and extends the coverage of \"design-time\" phases, classically addressed by the EP to \"run-time\" phases across the entire system life cycle. Additionally, the structure of the EP can evolve over time because the service-oriented Arrowhead-EP allows adding, removing, and modifying phases, the interactions between them and the stakeholders, and the associated tool chains. This particular feature is also supported by the Eclipse Arrowhead framework, where, starting from the EPP description, each EPP becomes a service: adding, removing, and modifying an EPP requires only a new version of the implementation that, once loaded in the EPMS, is ready to be executed. Continuous engineering is enabled by the presence in the EP of a coherent flow that extends from the \"Design-time\" to the \"Run-time\" phases of the EP, covering the entire system life cycle. The design and the development phases include all the phases preceding the system deployment, such as requirements elicitation, conceptual design, architectural design, implementation and testing, and prototype development [60]. \"Run-time\" phases cover the rest of the life cycle (the longest part from a temporal perspective), from system deployment and commissioning to standard operations, maintenance activities, identification of updates and future releases, until the system end of life, with retirement, decommissioning, and recycling, which is fundamental for the EU Green Deal objectives. Moreover, the presence of an _evolution_ phase and the possibility of creating feedback-based loops between EPPs is a fundamental enabling factor for continuous engineering. The automation and digitalisation of the EP extends from single-stakeholder EPs to integrated multistakeholder EPs because the Arrowhead-EP model allows us to \"connect\" the phases of two or more different EPs adopted by different stakeholders through the service-based interfaces of the EPPs. The coherence of data managed by the EP and the intellectual property issues associated with data sharing, data processing, and the execution of a multistakeholder EP are ensured by the adoption of an integrated solution and by the privacy and security features provided by the Eclipse Arrowhead framework across the entire life cycle of the system. The engineering of complex multistakeholder systems, very frequent in the IIoT domain, is supported by the possibility of interfacing, integrating, and managing different EPs adopted by stakeholders to design, develop, and operate the system components. The possibility of handling and automating an increased number of I/Os is guaranteed by the capability of the Arrowhead-EP to manage multiple I/O interfaces (i.e., services) for each EPP. The model is scalable since there is no limitation in terms of EPUs, which are simply and efficiently described in the ontology.