Digital Twinbased Cyber Physical System for Sustainable Project Scheduling In the presence of increasingly dynamic environments, frequent uncertainties, high customer specifications, strict project deadlines, and stricter requirements on sustainability, modern project managers are challenged in their ability to schedule and control projects. Thus, in the context of sustainable project scheduling problem, two important elements are to be considered as decision variables: the input elements of a scheduling (e.g. resources: workforce, machine, money) that enable the realization of a schedule for a project and the output element that are consequences of the realization of the project (e.g. completion time, energy, noise, pollution, waste etc.). In this context, integration of innovative approaches and concepts under the framework of fourth generation industrial revolution is must to build up a sustainable project scheduling model (SPSM). Considering this burning issue, this paper introduces digital twin (DT) technology and cyber physical system (CPS) principles to develop effective and efficient sustainable project scheduling systems and proposes a framework to show how they are interconnected through physical and cyber layers. The proposed framework is also applied to a reallife energy system as a case study for identification of the degradation of a physical layer.

Concept and Implementation of a CyberPbysical Digital Twin for a SMT Line This paper conducted research on the concept design and implementation of a cyberphysical digital twin system for manufacturing. Based on literature reviews and industry requirements for a cyberphysical digital twin system for manufacturing, this paper proposed a concept design architecture of a cyberphysical digital twin system and its implementation methodology. An application of building a cyberphysical digital twin system for a SurfaceMountedTechnology (SMT) line is illustrated based on the proposed concept and framework. The basic requirements of the proposed cyberphysical digital twin system are divided into three layers, i.e. operations layer, visualization layer, and intelligence layer. Operations layer is about systems modeling of the physical processes and establishing connections with the cyberspace. Visualization layer is related to the collection and displaying of the historical and present data in a visual manner. The intelligence layer is the ability to conduct data analytics and decision makings to identify patterns and bottlenecks, reduce waste, perform predictive maintenance, etc. A proof of the concept prototype is developed based on the proposed cyberphysical digital twin system for a SMT line.