**3.5 Optimizing resilience: Multi-criteria decision making (MCDM)**

Given that the purpose of the resilience and functionality level assessments is to reveal weaknesses, either isolated or in comparison with others (benchmarking), implementation of improvement measures is expected to be required. Which improvement measure(s) will be optimal to choose? Given a set of alternatives/ options various criteria need to be weighed against each other. This could typically include the effect on resilience (e.g. higher RL), costs and time to implement the measure(s), but also other criteria may be relevant. The method used to decide on optimal improvement measures is a Multi-Criteria Decision Making (MCDM) method and given that the nature of smart critical infrastructures and the resilience issues that they evoke tend to mix both quantitative (budgeting, performance indicators, etc.) and qualitative (expectations, procedures, etc.) aspects, it has to be able to address both semantic-logic and crisp numbers. Logical Multi-criteria decision-making (MCDM) methods are also preferable over other alternative decision-making frameworks because MCDM methods have "the potential capability of improving the *transparency*, *analytic rigor*, *auditability* and *conflict resolution* of decision-makers" [31]. Correspondingly, the MCDM provides:


The project considered various in-depth MCDM approaches that were used in other projects such as AIRM, PROMETHEE, and ELECTRE. However, during the eight case studies included in the SmartResilience and InfraStress projects, all of which involve end-user-owners of smart critical infrastructures, it became clear that the complexity of these methods made understanding them much more difficult and, at the same time, the required processing of the data needed proving to be prohibitively time consuming and expensive. Once an analysis is prepared and assessment data is input into the model (available on the project's ResilienceTool), the different optimization alternatives are scored following the combination of the user's input with the weighted criteria to rank the alternatives.

*Resilience and Situational Awareness in Critical Infrastructure Protection… DOI: http://dx.doi.org/10.5772/intechopen.97810*
