## 5 Simulation Results and Discussion
### Discussion of Results for the Semi-Urban Network  
The results show that the proposed methodology successfully selected investment options for different levels of DSO investment funds (Tables 9-11). In addition to selecting investment options for each considered funding level, the results demonstrate how each option individually improves the three observed indicators (Figures 5 and 6). Based on the reduction in the indicators, sorted from the highest to the lowest reduction, a sequence of option implementation can be applied. This sequence can prioritize options with a more significant impact on reliability improvement, ensuring that investments are directed toward the most effective strategies first.  
The analysis demonstrates that forming semi-rings through the construction of new lines has the most significant effect on reducing reliability indicators (_SAIDI_, _ENS_, and _COST_). Given the financial constraints, these options will be considered first if they fit within the available investment resources. Establishing semi-rings enables dual-sided supply, effectively minimizing outage duration for customers connected to the affected feeders.  
Calculations show that replacing old circuit breakers at the feeder's starting point, particularly those on feeders forming part of the semi-ring (CB5 and CB7), results in the next most significant improvement in the _SAIDI_ and _ENS_ indicators. However, when minimizing the _COST_ indicator, priority is given to circuit breakers CB7 and CB9, which are located on the 10 kV busbar section supplying feeders with a higher concentration of industrial and commercial consumers.  
The third most significant reduction in the analyzed indicators is achieved by installing remotely operated disconnectors with fault indicators. These devices allow for faster fault localization and network reconfiguration, significantly shortening the time needed to isolate the affected section. As a result, improved fault detection and isolation lead to a considerable decrease in interruption duration for end users. However, due to their higher implementation costs, the algorithm did not prioritize these investments when optimizing for _SAIDI_ and _ENS_. Instead, allocating the budget to multiple lower-cost solutions resulted in a greater overall reduction in these indicators. When considering the _COST_ indicator, the installation of RODs on the feeder leads to a more noticeable improvement in the indicator. As a result, in the case of the highest analyzed investment of EUR 250,000 (Table 11), the installation of RODs on Feeder 7, which supplies an industrial consumer, was selected as one of the implementation choices.  
The replacement of old disconnectors and fuses results in the smallest improvement in the analyzed indicators when considering all defined investment strategies. However, from the perspective of smaller investment planning, it is crucial to identify the transformer stations where replacing outdated equipment will lead to the most noticeable enhancement of reliability indicators.  
For the semi-urban network, Figure 7 presents the graphical results of the calculations assuming a maximum available budget of EUR 200,000. The figure shows that, when replacing old equipment listed in Table 6, all three indicators select the replacement of old circuit breakers, as well as the replacement of disconnectors in the line bays (D1 and D2) of the first substation, TS5, as optimal options. Furthermore, the selected options for _SAIDI_ and _ENS_ include the replacement of disconnectors in the line bays (D1 and D2) of the first substation TS33, located at the beginning of Feeder 9, while _COST_ indicator prioritizes the replacement of disconnectors in the line bay of TS6, which supplies both residential and commercial consumers.