## 3 Development of the Generic Implementation Strategy
### Methodological Fundaments of the Development
#### 3.1.2 Model Objective and Approach  
The objective of the GIS is to provide a targeted procedure for the practical realization of DTs in logistics systems of German rail transport, which fulfils the independently defined requirements from. The analysis of papers focusing on the implementation of DTs has shown that no paper is dedicated to the implementation of DTs in logistics systems. Furthermore, there is a lack of an implementation strategy that provides a detailed and generic procedure to support various DT implementation projects. If the claim of reproducibility is pursued, the strategy must not be limited exclusively to the documentation of a single DT project, as for example in the research papers by [PERSON] et al. (2018) or [PERSON] et al. (2020), because otherwise it can only be applied to a similarly specific project and thus lacks genericity. On the other hand, as shown in Section 2.3, DTs can be widely used in different industries and application fields. However, the value proposition of DTs varies greatly and results in different characteristics of DTs. The properties of DTs are therefore application specific. For this reason, the development of a GIS that covers all application fields and areas is not possible within the scope of this work.  
Regarding the primary requirements of the GIS, further orientations as well as derived benefits of the development can be identified. The GIS should continuously involve relevant stakeholders at an early stage and thus contribute to a goal-oriented implementation. In a research paper on barriers to supply chain data analysis in logistics companies, [PERSON] et al. emphasize the relevance of early integration of business interests and end users [56]. This socio-technical focus thus ensures that the strategy has sufficient stakeholder influence. Since changes can occur in the context of DT during the design and development process that are not foreseeable at the beginning of the design, an iterative procedure that also allows for changes in an already advanced development process is indispensable and a target component of the strategy [17]. Furthermore, the actual design and development of the DTs technical system remains fundamental and essential to the strategy. This was confirmed by all the papers analyzed.  
In addition to the aspects described the orientation of the GIS is also limited by the non-functional requirements. Since the concept of the DT includes a physical and virtual space that are connected via IoT sensors and represents an IT system with the presence of hardware and software, the strategy is aligned with the SE. Furthermore, the already described socio-technical system focus and forward engineering is aimed at. These represent, derived from the SE as well as the examined reference works, the following phases: _design_, _development_, _operation_, and _decommissioning_. This work examines a DT for a physically existing asset. Therefore, the life cycle of the asset is relevant and thus justifies the orientation of the strategy to the DT life cycle phases. This interaction of the life cycle phases of physical and virtual world, is of crucial relevance for the GIS development. The GIS aligns itself with plan-driven and dedicated process steps that have the sufficient level of detail to implement DTs. This means that the processes run as a series of phases and iterations between the individual processes occur (see Section 2). Conclusively, due to their relevance, the entirety of the requirements described is examined in combination for the first time in the context of science by this work and combined into a holistic strategy. Through it, the development of the GIS is oriented in the best possible way based on science and practice to logistics systems under consideration of German rail transport and thus contributes to the further research and development of DTs.