## 5 Case Study
### Connection Between Structured Features and Component Architecture  
This case study illustrates the process of connecting structured features with a component architecture visualized through a traceability matrix. Mapping between the structured features and initial components is performed by identifying the action value of the structured feature and linking it to the initial components. Figure 10 shows the results of mapping the structured features SF-001 to SF-021 derived from the functional requirement REQ_F_01 to their corresponding initial components.  
Figure 10: Mapping of initial components and structured features related to REQ_F_01.  
Figure 9: Structured feature list.  
'InitialSensorComponent' is a component that receives external stimuli into the system, and the structured features with the action value of \"Sensing\" are mapped to it. In the structured features related to REQ_F_01 in Figure 9, the features with \"Sensing\" values are SF-001, SF-008, and SF-015. These features are mapped to 'SensorComponent', whereas structured features with other action values are mapped to their respective initial components.  
In the case study, the software architecture was designed to facilitate software system modifications based on changes in the hardware elements that constitute the system [47]. InitialSensorComponent' is responsible for receiving all the stimuli for the target system. However, as shown in Figure 11, hardware elements that receive external stimuli exist in various forms, such as switches and CAN channels. In order to efficiently accommodate changes in hardware elements and improve modifiability, software functionality should be separated according to hardware functionality. Figure 11 depicts the portion of the architecture related to splitting REQ_F_01 to reduce the cost and time required to implement changes when modification requirements arise in the software system.  
The structured features initially mapped in Figure 10 are remapped to the components in the modified architecture as the component architecture is updated. As a result, 'InitialSensorComponent' is divided according to the position of the vehicle's door sensors, as follows: \"SenComAstDr' handles the function of the assistant knob switch; 'SenComRLDr' handles the function of the rear-left knob switch; and 'SenComRRDr' handles the function of the rear-right knob switch. Each component receives data from the knob switch at the respective position in the vehicle. 'InitialInterfaceComponent' transforms the data received by 'InitialSensorComponent' into a format that 'InitialControllerComponent' can process and that other components such as 'InitialActuatorComponent' can receive. There  
Figure 11: Mapping of components and structured features related to REQ_F_01.  
fore, it is divided according to the types of data that are processed. Structured features previously mapped to the original components are remapped using the structured feature-to-component remapping method. For example, because the output data value of SF-001 mapped to 'SenComAstDr' (Astunlockstate_raw) matches the input data value of SF-002 mapped to 'ConComDr', an operation is assigned to the interface Astdr between 'SenComAstDr' and 'ConComDr' using the method for assigning operations to the interfaces in SFCAD. This operation facilitates the transfer of data corresponding to 'Astunlockstate_raw' from 'SenComAstDr' to 'ConComDr'.