The chapter provides guidance on how the level of comprehensiveness needed in the determination of aggregate risks and risk undesirability scores is governed by the importance of the activity, the complexity of the activity, the novelty of the solution, the time available to make a decision, and the level of the organizational entity. It continues by defining a set of different levels of comprehensiveness applicable to different situations, wherein the levels of comprehensiveness are based on modulating the diversity and completeness of the scenarios, leading indicators, and performance measures that are covered so as to fit the situation. It goes on to identify and characterize simplified screening approaches that can be used to weed out inferior decision alternatives before more detailed analyses are conducted, and concludes by introducing a set of equations that may be used in place of more complicated computational models when performing a screening analysis.