## 4 Business Use Case Scenario for Testing--Users' Experience When Using the Platform  
To evaluate the effective operation of the proposed platform, a business use case (BUC) scenario for testing was adopted. The BUC associated with the project is the one related to the enhanced active/reactive power management for the coordination between TSOs and DSOs. The weather service provider delivers the high-resolution weather forecast for the area of interest, as can be seen in Figure 11.  
Based on the weather forecast, the system operators obtain the forecasts of the selected power system parameters, such as the production of the renewable sources, the demand power, and the transmission capacities of the lines. The unified view for all the RES integrated in the part of the system of interest (for the predefined period of time) is given in Figure 12.  
In addition to this, there is a possibility of extracting the hourly results only for a single RES that is of interest for the user. This can be seen below, in Figure 13.  
The SOs update the unified grid model with these parameters and perform the generation optimization process, with the results of the load flow calculation on the created model indicating that the potential problems in the system could arise if no action is taken. The example of such a model, shown on the georeferenced map of Crete Island, is given in Figure 14. If there is any other region selected by the user for analysis, the map of Crete Island and the grid on that island can be replaced by the chosen region, under the condition that there is enough input data at disposal of the user so that the model can be rearranged properly. Figure 11: Georeferenced presentation of load flow results. Figure 12: RES production for the analyzed period. Figure 13: Single RES production by hour. Depending on the nature of these issues and the services that could help in relieving the situation, there were three scenarios defined within this BUC:  
1. The one considering the contingencies in the grid, where the high loading or even the overloading of the line is detected; this can easily be spotted since the GUI used for the presentation of the results uses the color coding of the lines to show their loading (Figure 15). Particularly, the red color of line 3 from node 12 indicates that this line's loading is close to the permitted limit (between 80% and 90% of the maximum allowed transmission capacity); the darker red shade would mean even higher loading. 2. The one considering the occurrences of the voltages out of the predetermined boundaries (this could either be warning of too-high voltages or warning of too-low voltages);  
Figure 14: Georeferenced model of Crete Island. Figure 15: Example of the high loading of the line. this can also be seen directly from the georeferenced map, Figure 16, of the system, in which the color of the node in the grid indicates the value of its voltage, in line with the legend shown on the left-hand side of the map. Once the problem is identified, the flexibility services that could mitigate it are defined and forwarded to the MO to initiate the process of acquiring the services. The view of the list of defined flexibility resources that can provide the service is given in Figures 17 and 18, in which the FSP register is included. The FSP register is populated only with FSPs that have passed the proposed and implemented prequalification process. This list can easily be extended by adding new flexibility resources, as shown in Figure 19.  
Figure 12.0 The way of showing the voltages in the map. Figure 12.1 List of defined flexibility resources. After that, the MO sets up an auction in which the SOs can pick the necessary services, along with the prices that can be paid for those services. This is performed in a quite simple manner, by following the instructions enclosed in the Auction Wizard of the F-channel platform.