Chapter 1 introduced an approach to modeling a mission functionality dependent network consisting of only functional components, i.e., components that are activities in support of a mission. Chapters 2 and 3 enlarged the mathematical possibilities for how such mission networks can be modeled and analyzed: Chap. 2 did this with a continuous variable framework, and Chap. 3 did this with a discrete variable framework. This chapter takes a “third eye” view and enlarges the Chap. 1 analysis in a different direction using Operations Research (OR) methods: It acknowledges that in some mission planning and analysis, a mission success depends on the ability to accomplish multiple activities, which in turn depend on the functionality of supporting physical systems. These physical systems may lose functionality due to, for example, cyberattack, natural disaster, or aging infrastructure. It is therefore imperative to understand and characterize the risk that each system poses to overall mission effectiveness. Furthermore, this chapter acknowledges and addresses the realist possibility that the parameters that characterize the mission are not known perfectly.