## 4 Discussion: Model for G-QMS in SoS
### G-QMS in SoS, Sturcure
#### 4.3.2 G-QMS in SoS Interfaces  
In Figure 2, an independent category [8.5] was identified for this topic with a Si\({}_{\text{Total}}\) = 8.27, recognized across all five clusters, notably by the Light-Rails cluster, contributing 88.1% of the Si. The G-QMS in SoS interfaces are elaborated in the following sections. 1. **Interface entities** Within G-QMS in SoS model, QMS\({}_{\text{int}}\) entities assume a significant role, especially since they encompass _technological system_\(QMS_{int}\) entities as well. These entities participate in facilitating interoperability within the SoS, enabling effective communication and integration among the various constituent systems to form a more complex, higher-order system. The notable example is the identification of the unique QMS\({}_{\text{int}}\) located between the QMS\({}_{\text{Integ. }}\) and the QMS\({}_{\text{CS}}\) (denoted by QMS\({}_{[\text{integ.}\text{CS}]}\)). Moreover, the development and enhancement of interoperability are critical across all entities within the G-QMS in SoS, ensuring effective coordination and communication throughout the system. 2. **Professional expertise and transdisciplinary management** The G-QMS in SoS model demands a high level of professional expertise and transdisciplinary management. This complexity and deepness transcend the capabilities of traditional quality management, necessitating professionals in quality fields and QMS entity leaders--who are conceived as persona--to exude validity and professional authority (See also [PERSON] and [PERSON] [2]). Additionally, the model requires a systemic, holistic, and transdisciplinary view, echoing the necessities identified in the G-QMS of Org. of SoS model [2]. Both are necessary conditions, without which the G-QMS in SoS will not be able to provide the added value for the SoS projects, which are naturally complex and integrate advanced technologies and span large scales and scopes. This lays on two pivotal elements: The first is _a strong emphasis on interface management_. A critical aspect of this model is the emphasis on managing interfaces, which includes not only the interactions among QMS entities within the organizational structure, seen also in G-QMS of Org. of SoS model [2], but also, importantly, the technological interfaces or interoperability among the CSs of the SoS. Given the large scale and complexity of SoS, managing these interfaces becomes increasingly significant. The focus should be on characterizing and implementing these interfaces effectively, particularly the interoperability among the CSs, as these points are _potential weaknesses_ but also _opportunities for enhancing_ the SoS's success. Furthermore, the model must consider the SoS project's interfaces with the client, the other stakeholders on his behalf, and the operational environment, such as regulatory bodies and municipal regulations in the case of sectors like light rail. Managing these interfaces is central to SoS project management, necessitating dedicated executive methods and specialized teams equipped with the needed expertise, including these for defining interoperability among the CSs and the SoS that combines aspects of which the CSs are completely unaware. Thus, the G-QMS in SoS should include functions specifically designed for comprehensive interface management, ensuring effective communication and coordination across all levels of the project. The second crucial element is the capability to _coordinate and combine activities within the G-QMS in SoS framework_. This model acts as a management entity that undertakes the coordination and combination of efforts in a transdisciplinary manner, leveraging the quality work carried out by the various responsible QMS entities. This requires a transdisciplinary approach to manage the diverse outputs originating from multiple sources across the breadth and depth of the entire structure, including both external and internal QMS entities.