 some parts of the network Proactive communication on the diminished levels of service to all consumers and stakeholders These are clearly short-term strategies to ensure the impact of challenges is mitigated and acceptable levels of service are recovered as soon as possible. Prevention Strategies Prevention strategies are more long term and also take more effort to plan and implement. These could include: Structurally improving parts of the system to ensure KPIs are not vulnerable to challenges Proactively improving parts of the system that may prove weak to challenges by improving design, algorithm, technologies, or other implementation aspects or using improved antichallenge measures in the system Simulation and Modeling techniques The use of simulation techniques is one way to develop models to simulate the network at different levels of service, generate the challenges, and observe the impact on the KPIs. The results could be fed into the model to generate possible measures to mitigate and preempt the challenge. Simulation and modeling require a lot of tooling and domain expertise as well as much effort and cost to set up. CHAPTER 6 A PROCESS FOR NETWORK ROADMAP EVOLUTION Define Resilience Strategy: Output Resilience Strategy The actual resilience strategy as an output should include: A table that presents the service levels, challenges that impact the service level, and the KPIs that are impacted under these challenges with mitigation and prevention strategies A way to document or review the resilience response and ensure the strategy remains relevant and current This information becomes input to the roadmap planning and review to ensure resilience is ensured in the roadmap for the levels of service that are targeted. Perform Network Resilience Review To be able to define the resilience review strategy, we could start with defining the service levels that are acceptable for the network. Figure 6-13 outlines this process. Input Tools and Techniques Resilience management Output KPI variance analysis Resilienc