## 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  
In Figure 2, the results for SoS project management are abundant in the independent category [8.2] with SiTotal = 18.78. All five clusters referred to it, with the SoSE cluster notably contributing 57% of the Si. The management process of a SoS project encompasses distinct features that necessitate corresponding support from the G-QMS in SoS. These key features of the SoS project management process directly influence the design and function of the G-QMS in SoS, underlining the need for a QMS that is adaptable and robust enough to cater to the unique demands of managing SoS projects. 1. _SoS project management process structure is longer and extended:_ The structure of the SoS project management process is notably more extensive and prolonged, diverging from conventional models by incorporating additional stages (along the longitudinal axis) and expansions (on the transverse axis). In Figure 2, subcategory [8.2.1] with SiTotal = 5.66 was identified for this process, with the SoSE cluster contributing 55.7%. On top of it, this special process structure is further elucidated through other related subcategories. 2. _SoS design process through horizontal blocks_: A strategy aimed at managing the high complexity inherent in these systems. This is an example of expansion (on the horizontal axis) that allows for the segmentation of the design phase into manageable sections. It is highlighted in Figure 2 in subcategory [8.2.2] with a SiTotal = 2.57 and predominantly contributed by the SoSE cluster (75.9%). This is an essential, necessary concept in SoS, starting from the planning stage, and aims to obtain design outputs along the defined milestones through the project development and not only at its end, thereby reducing the risk level in the development. Each horizontal design block encompasses a set of CSs along with their specific designed contents. This method not only aims for the design planning of the blocks in a _balanced way_ among the CSs but also strives to plan these blocks as _independently_ as possible. The significance of quality management within this design stage emerged prominently in the research findings, underlining the critical notion that a system's quality is fundamentally rooted in its design. Despite its importance, quality management in the design phase is observed to be less advanced compared to other project areas, indicating a potential area for further development and focus in SoS projects. 3. _Expanded quality assurance mechanisms for approving entry of CSs to SoS C&1 stage_: An entire quality management area that involves diverse quality processes (see Section 4.4.2) and relies on the QMSCS. QMSCS is responsible for providing each CS with an extended Certificate of Compliance (COC) along with additional extended quality references, denoted as a process extension. In addition, in accordance with CS classification, a modular (multi-stages) control process structure is implemented, start ing with the CS approval at the CS organizational site through to its final validation approval, obtained by the successful completion of the SoS validation experiments. 4. _Combinations and Integration (C&I) stage_: This represents a critical and highly complex phase in SoS projects, carried out in an elaborate and multi-phased manner. This stage is particularly notable for its final integrated phase, which involves comprehensive testing at the level of the fully integrated SoS. The C&I process is found at the core of the SoS, a pivotal feature of SoS project management. In Figure 2, subcategory [8.2.3] is identified for this process stage with a SiTotal = 9.28. This was noted across all five clusters, specifically by 67% of the respondents in the SoSE cluster, contributing 53.3% of the Si. The C&I process unfolds in three phases after a _preliminary phase_ of the SCs installations. The _first phase_ involves thorough testing of each CS in isolation to ensure full and systematic verification of its functionalities.