Problem Statement
When developing a long-term access network transformation plan, network operators tend to focus on demand growth as the key trigger for upgrades. While accommodating demand growth remains a key driver for upgrading a network, in reality other triggers may enforce a different upgrade strategy and alter the preferred upgrade path and the required investment profile. Hence to select a suitable upgrade strategy, it is imperative to understand the robustness and sensitivity to input assumptions against a complete set of relevant upgrade paths.