Influence of Parameter Uncertainty in Multi-Criteria Decision-Making When Identifying Optimal Retrofitting Strategies for RC Buildings

The evaluation of retrofitting alternatives through multi-criteria decision making (MCDM) approaches allows an optimal selection based on a ranking system. This rank depends on evaluation parameters that assess particular aspects of the retrofitting options and influence the selection of the most advantageous alternative. Moreover, when integrating uncertainty of the input parameters into the procedure, the outcome may be altered and the rank order notably different with respect to a deterministic MCDM implementation. This paper examines an MCDM approach applied to four retrofit alternatives proposed for a case-study building, starting from a deterministic perspective. Subsequently, the MCDM method is extended to consider random variables, in order to compare and understand the influence of uncertainty of the input parameters in the selection of retrofit alternatives for the same building. To ensure that accurate and representative data was used in the stochastic implementation, an ad-hoc survey was developed to collect the views from relevant parties involved in the field of seismic retrofitting interventions, particularly those with an academic/research or practice/industry background. The outcomes of the study are believed to serve as useful guidelines and as a future reference for practitioners in the field of structural retrofitting, on how to select the most convenient retrofit alternative for an existing building.