# A Categorization of Digital Twin and Model-Based System Engineering Interactions
## 3 Results
### Interaction Between DT and MBSE  
The focus of this section is to analyze the types of interactions among DTs and MBSE presented in the selected articles and to describe them. [PERSON] et al. [18] argued that DT technology should be part of the MBSE methodology and suggested that it will become a key feature in the future. The MBSE model can be seen as the authoritative source of truth for the system during its design phase; however, the DT can extend this reach throughout the life cycle of the system. This can be achieved because a DT is a virtual representation of a specific instance of a physical asset. Additionally, DTs can take advantage of MBSE constructs, languages, and techniques to enhance the virtual representation of the system, as well as to evaluate the system's behavior on virtual testbeds. [PERSON] et al. [26] classified DTs in the manufacturing context on the shop floor into three categories: product, process, and operation DTs. The first type is related to the product that was manufactured. The second is intended to support the production process. The third is responsible for simulating and analyzing the interactions between the components of production. Although the authors did not explicitly refer to MBSE, the models used were equivalent or similar to those of this methodology, including behavior models using Petri net-based models and collaborative information models using SysML. [PERSON] et al. [27] proposed the concept of an experimentable digital twin (EDT), which is a DT for the simulation of different scenarios of the system in virtual testbeds. The system modeled using MBSE methods and tools is used as a basis for these simulations. The EDT can be linked directly to SysML blocks, requirements, and the test cases developed. [PERSON] et al. [28] discussed their experience and the difficulties encountered while constructing a DT project. They suggested a standard data format for communication between software programs in the DT environment. Their DT was designed using SysML in IBM Rational Rhapsody, with blocks made up of Simulink, Dymola, Modelica, and Rhapsody models. SysML was employed in allocating requirements, formally defining the system's logical behavior, and aiding integration. [PERSON] and [PERSON] [29] suggested that product data management (PDM) can be linked to both MBSE and DTs. According to the authors, MBSE models can provide data from the initial design stage, while DTs can give a snapshot of the system at any point after the production phase. The authors proposed that blockchain technology be combined with MBSE models and DTs, allowing for traceability of changes throughout the system's life cycle securely and transparently. In this context, MBSE and DTs do not interact directly with each other. In contrast to other studies, [PERSON] et al. [30] proposed a DT for the design process itself. This DT was employed for complexity assessment, effort estimation, and the forecasting of change propagation during the design stage. The authors used SysML and profiles to construct the DT. [PERSON] and [PERSON] [31] suggested that the DT and digital thread can be used to enhance system engineering by integrating MBSE models and engineering models during the initial design stages, as well as keeping these models up to date throughout the system's life cycle. Furthermore, they discussed the benefits of adopting the DT for each development phase. [PERSON] et al. [32] proposed a methodology to develop a DT in parallel to the MBSE system model. This approach can lower the cost of DT development compared to its development after the system is deployed. MBSE defines the standards and ontology of the system, which can improve the DT. In addition, its models can evolve and become part of the DT itself. [PERSON] and [PERSON] [33] combined a DT and MBSE with variability modeling using the concept of the EDT, as proposed by [27]. To simulate and support decision-making, the DT uses the system itself and its variants, modeled by SysML.