d on the common understanding of framework that needs to be developed for network resilience to be defined. It is possible that this may not apply to a specific resilience strategy used by the actual network. Define Service Levels To be able to define the resilience strategy, you could start by defining the service levels that are acceptable for the network. Figure 6-10 illustrates this process. Input Tools and Techniques Resilience management plan Output Network KPI Enterprise/domain analysis Defined levels of factors Critical incidents service Organization input analysis Figure 6-10. Definning the service levels Define Service Levels: Tools and Techniques Network KPI Analysis To define acceptable levels of service, one could start with critical KPIs that determine how the network performance is perceived. Network KPI analysis tries to determine discrete points determined as a combination of KPI levels that give an indication of availability, dependability, reliability, trustworthiness, and other critical aspects of the network. Critical Incidents Analysis Analysis of critical incidents when the network was subjected to external challenges could also be a valuable tool to determine how the network behaved and to project service levels based on such behavior. Define Service Levels: Output Defined Levels of Service The output of the define service levels process is the actual levels of service definition, which would include: Clearly defined levels of service Each level of service characterized and defined by measurable KPIs of the network Optionally each level of service could also include vulnerabilities for that level of service and the source for it CHAPTER 6 A PROCESS FOR NETWORK ROADMAP EVOLUTION Perform Challenge KPI Impact Analysis To be able to define the resilience strategy, you could start with defining the service levels that are acceptable for the network. Figure 6-11 illustrates this process. Input Tools and Techniques Resilience management Output Standard resilience Defined levels of dervice challen