There is a large body of work and effort been made in the modelling of critical infrastructures (CI's) by academia, enterprises, stakeholders, operators, etc.; however, their endeavours have received mixed success so far. This can be traced back to several difficult and historical hurdles in CI modeling such as the chronic unavailability of reliable and recognised data, the specificity of the resulting model, and therefore, its application, the underlying mathematics, narrow-mindedness and lack of awareness of the consequences of infrastructure failure, the recognition and dissemination of the modelling methodologyknowledge, etc. Consequently, bridging theory and application and providing tools for analysing CI's is key to ensuring that such modelling delivers the benefits voiced and satisfies the needs raised. This chapter sets out to tackle several of these issues.