## 6 Conclusions  
In Italy, the allocation of budgets is unsystematic since no solid principle has been established. In this regard, decision makers face a challenge given that there are a large number of vulnerable buildings. This project was inspired by the idea from the aforementioned missing point in the seismic risk management of building portfolios. It attempts to develop a decision-making procedure to figure out how to distribute the budget not casually but wisely and with cogent reasoning. The study has been built on the platform of seismic risk analysis of buildings to understand how to manage budgets in order to lessen the future risk. The seismic risk is calculated in dimensions of monetary loss by combining the data of hazard, vulnerability and exposure. The algorithm for making decisions about how to reduce the seismic risk of an entire portfolio has been established by estimating the cost of retrofitting and calculating the benefit gained due to such an investment. The vulnerability index of buildings has been used to distinguish buildings that are vulnerable or not. Four intervention strategies have been assumed as possible interventions for each building: demolition/reconstruction, no intervention, partial retrofitting and full retrofitting. The best choice of intervention has been defined as that which meets both the needs and limits of the clients. From all of the combinations of interventions for each of the buildings the total cost and total seismic risk of post-intervention configuration can be calculated. The optimum selection of decision strategies is the one requiring a cost lower than the budget limit and yielding the minimum seismic risk in post-intervention. Finally, it is established how to intervene for each building and how much should be spent for each building to achieve the perceived minimum seismic risk. A web platform system has been developed with the collaboration of ETT industrial partner within the framework of the GRISIS research project. The platform is able to provide a practical map of the seismic risk of a certain stock of RC buildings in the pre-intervention condition, particularly indicating the contribution of each building to the overall seismic risk of the portfolio. In a different section, geo-referenced data concerning a building's identity and geometry are stored. Then, an interactive section of the web system allows the user to insert the available budget to be allocated for the seismic risk mitigation. Knowing this, the system provides the optimal strategy for the budget's use and the corresponding post-intervention seismic risk map. In particular, the system is able to inform the user about (i) the retrofit intervention to adopt for each building of the portfolio, (ii) the post-intervention seismic risk in correspondence with each building and (iii) for the whole portfolio, (iv) the occurrence of each intervention typology in the portfolio and (v) the budget allocation for each type of intervention. The use of the platform is shown through the applicative case study concerning the seismic risk mitigation of an RC school building portfolio distributed in the territory of the Campania region in south Italy. Supposing the availability of EUR \(2.5\times 10^{7}\) investment for the portfolio's seismic risk mitigation, the platform provides the best budget allocation corresponding with intervention on 28.3% of buildings. In particular, one building was to be demolished and rebuilt because it was characterized by very severe vulnerability, while 26% of buildings were equally distributed among partial and full retrofit solutions. An investment of 58.6% of the budget was spent on full retrofit interventions, while 32.1% was spent on partial retrofit buildings and 9.3% of the budget for the demolition and reconstruction. A sensitivity analysis concerning the variation of the budget value has shown that for lower values partial retrofitting is preferred with respect to full retrofit strategies. The trend is inverted when the budget rises.