## 3 Development of the Generic Implementation Strategy
### Generic Implementation Strategy in the Narrower Sense  
#### 3.2.1 Phase 1: Design Phase  
The life cycle phase of the design is used to design the DT prototype. Contrary to the use cases of DTs, where assets in the production industry are designed and developed with the help of DTs, the considered use case focuses on assets that already physically exist. The design of the asset is therefore neglected in this phase and is not considered further, so that the focus lies on the DTP and its DTE. Within this phase, the requirements for the DT are defined at an early stage to enable a targeted implementation. With reference to Table 1 of the layered structure of socio-technical systems, the design of the DT begins with an analysis of the entrepreneurial environment in which the DT is to be implemented. This step serves to understand the entrepreneurial characteristics and is in line with the socio-technical system focus. In addition to the analysis of regulations and guidelines as well as the corporate strategy and mission, the focus primarily lies on the identification of concrete objectives and problems, or ultimately of operational challenges that serve to characterize the solution. When identifying the solution, it is essential that the solution is chosen based on the challenges and that the DT is not the predefined solution. This is important to ensure that the best possible optimizing solution is chosen for the existing challenges, even if the solution does not include the DT. To ensure the greatest possible objectivity, alternative solutions are also identified and compared alongside the characterized solution. This should serve to avoid the phenomenon of _overengineering_[16], which causes a non-beneficial technical playfulness due to an intrinsically over-optimal manner for technical perfection and quality [57]. The operationally optimal solution is then further specified with an initial operational concept, which provides information about elementary stakeholders, the expected life cycle, and the operational environment. This preliminary operational concept serves as the basis for the subsequent processes. Based on this, it is useful to conduct a risk analysis [54]. This process step could not be identified in its entirety in any of the research papers analyzed. Only [PERSON] et al. mentioned that it is very important to understand the environment in which the DT will be used. This low occurrence may be related to the fact that the use cases and the environment in the analyzed works are already fixed, and the works have a very technical focused character, without the presence of a generic approach. Another important aspect is that the focus on operational optimization is not firmly anchored in some cases and thus the dedicated business analysis is not in focus. Nevertheless, the described fields of action and objectives of this first process are elementary for the implementation of a DT, as they enable the described operationally optimal solution finding and the identification of company environment-specific characteristics (see Figure A2). After defining the business context and the operationally optimal solution, the next process step includes the identification of stakeholder needs related to the identified DT and its life cycle, what serves to prepare the DT requirements that will be placed on the implemented DT by the users and its environment. Regarding the stakeholders, there is a strong focus on the involvement of end users to ensure a user-centric solution. For this purpose, the operational system concept is specified, which shows possible interfaces and interactions between end users and the system to identify necessary needs and requirements. In order to overcome possible hurdles, as users do not have sufficient expertise for the technical design of the DT, methods of _end-user development_ (EUD) design can be applied [17]. Once all stakeholder needs have been captured, they are translated into concrete requirements. This means that constraints are identified, and qualitative requirements are defined.