monitoring

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DEFENSE SCIENCE BOARD | DEPARTMENT OF DEFENSE
highlighted the stewardship of problem definition as a necessary and important element in the
set of capabilities to combat the problem itself.
Scenario based planning approaches can also have shortcomings if not appropriately
implemented. For example, while useful for highlighting specific trade‐offs, a limited set of
scenarios can generally only cover a small subset of the variables that an analyst might want to
explore, thereby artificially narrowing the problem space. Utilizing a wide set of end‐to‐end
scenarios can become cumbersome and difficult to assess systematically. Additionally,
conclusions drawn from a narrowly defined set of specific scenarios can be fragile to “what‐if”
challenges, where the scenario details beyond those explored in the analysis are modulated,
casting uncertainty on the results and raising the risk of invalidation. Scenario authors also run
the risk of fixating on “favorite” scenarios, or those that mirror their own preferences and
biases, which can prevent systematic and objective thinking. Finally, a non‐systematic scenario
approach can exacerbate the problem of mapping scenario details and analysis to a structured
decision methodology.
Rather than utilizing a small set of well‐defined scenarios with the risks and shortcomings noted
above, the Task Force developed a scenario framework that attempts to encompass a large
portion of the potential scenario space in order to address the totality of M&V problem
complexity. A scenario framework for scenario generation
and analysis is desirable primarily because it enables the
examination of a family of scenarios, rather than a small set
of independent and specific scenarios. It also provides a
systematic method for decomposing scenarios into discrete
nodes and linkages, and capturing the interdependencies
between individual scenarios. Finally, it lays the foundation
for a bridging methodology, or systematic mapping between
the problem space and solutions space, that enables
increased traceability between planner objectives and
solution performance.
In constructing an example scenario framework, the study
team began with a simple premise: a scenario is a linear
series of events can be broken down into discrete nodes and
associated linkages, and systematically analyzed, node by
node. Error! Reference source not found. shows a simple
sequence of nodes within the framework to illustrate these
concepts. In this example, the failure of a nation’s NW Figure A‐2 Example Node Sequence
security structure (e.g. compromise of storage site security,
material stolen by an insider) begets an evolution of
subsequent scenario actions. Such a failure could lead to the theft or loss of a weapon from the
custody of a nuclear weapon state. This theft could lead to the transition of a weapon to a non‐
DSB TASK FORCE REPORT Appendix A: Unabridged Description | 81
Nuclear Treaty Monitoring Verification Technologies
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