# Resilience Quantification of Smart Distribution Networks--A Bird's Eye View Perspective
## 6 Conclusions  
In this paper, state-of-the-art studies on resilience quantification of smart distribution grids are summed up with the perspective to analyze all involved tools and point out assessment objectives. Performance calculation is identified as the main enabler of resilience evaluation, as almost all reviewed metrics rely either exclusively on operational performance measures, or as a mix of operational and topological parameters. Many models are proposed in the literature to compute performance, among which system modeling is the most dominant with a focus on four main aspects: contingency, fragility, restoration, and functional dynamics. Empirical models serve as baseline and data feeder for system models, whereas surrogate models try to bypass network modeling by the harness of advanced machine learning techniques to directly infer performance measures from various topological, topographic, and operational parameters.  
Distribution grid resilience is defined in reviewed research in the face of HILP events which need to be foreseen using forecast data, historical records, estimation tools, and contingency models. Accentuation is made on the difficulty to design resilience for multiple events, especially with the fact that enhancement strategies can be very specific as they are advantageous in some cases and not in others. In addition, we propose a classification based on the time of resilience evaluation, which allows projecting real case applicability of presented assessment frameworks. The resilience phases-based approach was linked with different objectives of the assessment, from simple metrics evaluation, to either planning or response for survivability and recovery; achieved through a variety of improvement strategies for which allocation is optimized under the constraint of a limited budget. This bridges resilience studies and economic considerations in order to help stakeholders in investment plans elaboration and crisis management decision-making.  
Aspects of critical load, microgrids, and uncertainty of hazards, load, and distributed generation are discussed to show their high importance, and explain available tools so far for their involvement in the study. Finally, a demonstration was made on ahead steps that resilience studies in the electric domain have compared to telecommunication domain, and an urgent need to level up the two for complete joint resilience analysis of smart grids, unlike current separate works that neglect several pertaining interdependencies. Therefore, future works need to focus on coupled electric-ICT networks with joint quantification frameworks, which not only consider the resilience of the coupled system, but seek further granularity by investigating constituent applications and functions such as distribution automation, automatic metering, and grid management.  
Methodology, formal analysis, investigation, writing--original draft preparation, Y.N.B.; methodology, visualization, supervision, writing--review and editing, P.C., J.S.-T., Y.-P.F., Z.Z., A.B. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Authors would like to thank the reviewers for their insightful comments and constructive suggestions.  
The authors declare no conflict of interest.