A Method for Deriving Technical Requirements of Digital Twins as Industrial Product-Service System Enablers

Abstract

Industrial Product-Service Systems (IPSS) are increasingly dominant in several sectors. Predominant value-adding services provided for industrial assets such as production systems, electric power plants, and car fleets are remote asset maintenance, monitoring, control, and reconfiguration. IPSS designers lack methods and tools supporting them in systematically deriving technical design requirements for the underlying Cyber-Physical System (CPS) IPSS services. At the same time, the use of Digital Twins (DTs) as digital representations of CPS assets is becoming increasingly feasible thanks to powerful, networked information technology (IT) and operation technology (OT) infrastructures and the ubiquity of sensors and data. This paper proposes a method for guiding IPSS designers in the specification and implementation of DT instances to serve as the key enablers of IPSS services. The systematic mapping of the continuous IT design-build-deployment cycle concept to the OT domain of CPS is at the heart of the applied methodology, which is complemented by a stakeholder-driven requirements elicitation. The key contribution is a structured method for deriving technical design requirements for DT instances as IPSS. This method is validated on real-world use cases in an evaluation environment for distributed CPS IPSS.

Towards DevOps for Cyber-Physical Systems (CPSs): Resilient Self-Adaptive Software for Sustainable Human-Centric Smart CPS Facilitated by Digital Twins

“…In the first and second phases, we investigated architectural concepts, design patterns, and requirements engineering methods from diverse research and industry domains, including cloud, edge, embedded, self-adaptive, service-oriented, and Cyber-Physical Systems. Based on our investigations, we have published several concepts and design patterns [17,21,38], as well as a novel requirements engineering method for the use of Digital Twins in IPS2 [6]. We applied this method to derive the requirements and design of generic self-adaptive system models that facilitate DevOps for CPS, which we published in [31].…”

“…This ecosystem facilitates value optimization for all stakeholders along the value chain by integrating and coordinating various aspects such as the planning, development, provisioning, operation, and utilization of products, services, and immanent software [4,5]. To satisfy stakeholder needs, the individual ecosystem elements must be able to adjust their behavior to the system's operational context, considering different states and goals at varying proximity and time scales [6,7].…”

“…These trends create a need for smarter CPSs that continuously align their architecture and governance to the concerns of various stakeholders, including developers, operators, and users [6,8]. Such smart CPSs are even more software-intensive than traditional CPSs and can be characterized as systems realized through the dynamic composition of autonomous and heterogeneous resources that interact to provide users with rich functionalities.…”

“…We conducted a multi-stakeholder analysis to identify the technical IPS2 and Digital Twin requirements to obtain an integrated view of business, customer, and provider needs, which we published in [6]. Our analysis finds that CPS providers in the IPS2 context face particularly high risks due to design uncertainty [20].…”

“…Hence, our approach is to enrich the fundamental CPS elements-particularly the secondary assets' computing capabilities-with the capabilities necessary to manage continuous change. Depending on proximity and time scales [6], the change-management processes of the AdEpS model are driven by either humans or machines. This is illustrated in Figure 1a through the machine-driven CPS self-adaptation and the human-driven CPS evolution capability elements.…”