A risk has been realized… Now what?
John Q. Todd, John Dokken · 2011
This paper describes the proposed implementation of “Data-Rich Sequence Diagrams” in association with top events from Fault Tree Analysis used for risk assessments at the Deep Space Network (DSN). 12Given the probability of a top event, “the risk”, there will be actions taken and further events occurring after the risk manifests itself. By diagramming the initiating risk event, the pivotal events and potential end states, an organization can visualize the paths to success (and failure) post-risk occurrence. In addition, with appropriate supporting data, the probability of success/failure of any particular event or entire path can be assessed. Diagrams of this type provide an excellent visual (an analytic) tool to confirm the steps being taken and clarify outcomes, both good, bad, and all ranges in between. Using diagrams of this nature expands our use of Probabilistic Risk Assessment (PRA) at the DSN. Assessing the risk of a particular service outage during a mission is only the first step. With Data-Rich Sequence Diagrams we can quickly visualize missing elements of our response to a manifested risk, determine potential end states, and even perform simulations of risk scenarios for dry-run and training purposes.