## 4 Discussion: Model for G-QMS in SoS
### G-QMS in SoS Structure Supports the SoS Project Structure
#### 4.2.2 SoS Project Management Prism
The _second phase_ focuses on the testing of interfaces, initially between individual CSs and the SoS, gradually expanding to include as many interfaces as possible to test the interoperability between multiple CSs. The _third phase_ entails testing the fully integrated SoS as a whole, ensuring that all systems function together as intended. In SoS projects, the C&I process is significant since most of the problems are found in the interfaces (connections). As more systems are connected, interface complexity increases exponentially. The research results highlighted that this structured approach to the C&I process is instrumental in addressing the challenges posed by the _emergence property_, which is particularly dominant in SoS projects. The more the emergence phenomenon is revealed in the fully integrated SoS testing--the final phase, the more complicated and expensive it is to solve, and therefore, a modular multi-phase process makes it possible to reduce it as much as possible. A lot of resources are found to be invested in the C&I process, including the testing's application in extensive laboratories and using specialized simulators designed to simulate the fully integrated SoS as much as possible. The responsibility for the C&I process, including the conduction of tests, falls to specialized SoS engineers. In highly complex and large-scale SoS projects involving expansive G-organization structures, a dedicated Integration organizational body, sometimes a specialized organization, may assume this responsibility on behalf of the SoS project's chief management. Beyond the planning and execution of C&I tests, the Integration body ensures that the project's process structure, which involves multiple partners, operates as intended. This is the technical owner that integrates all the systems of the SoS in the project, whose primary objective is to guarantee the successful completion of the C&I process. Structurally, the Integration body oversees the Interfaces management and the Testing and Commissioning (T&C) management, each led by a manager and supported by technical staff. Quality management during the C&I stage entails an assurance process C&I process itself, culminating in the confirmation of the owner at the end of the process, before proceeding to the validation stage through experiments. This assurance utilizes quality tools, common also in the previous project stages, but suitably adjusted for the C&I stage. However, like the design processes, quality management in the C&I stage is often found to be under-defined or underdeveloped, highlighting a clear need for its advancement. This research contributes to advancing quality management in these critical areas by identifying relevant quality management entities within the model: \(QMS_{\textit{intreg}}\), \(SoS\)_QMS T&C, SoS QMS_handing over, and the contents required within these entities. 5. _Validation stage experiments_: Another example of longitudinal expansion. In Figure 2, a second-order subcategory [8.2.3.1] is identified for this topic with SiTotal = 1.27. The validation stage in SoS projects involves a series of critical experiments designed to verify the SoS's functionality and performance. For instance, in the rail sector, this stage includes dynamic tests when a train is operational on the track, and similarly, in the aviation sector, it encompasses experimental flights. The more complex the SoS project, its scope of experiments is greater, and it is carried out through a longer multi-phase process to ensure that each system of the SoS functions as expected in real-world conditions, and the entire SoS meets the required standards and specifications. (f) _Handing Over phase_: Another example of longitudinal expansion. In SoS projects, the transition from project completion to operational use involves a structured handing over phase, where the SoS is formally transferred to the client or an appointed operator.