ABSTRACT
Probabilistic. scenario. analysis. (PSA). refers. to. a. bundle. of. tools. and. techniques. that.make.use.of.scenarios,.probabilities,.and.probabilistic.analysis..Most.quantitative. risk.assessments.are. likely. to.be.some.form.of.probabilistic.scenario.analysis.. Deterministic.quantitative.risk.assessments.would.be.the.exception. Many.decisions.are.hard.because.they.are.complex..They.involve.inherent.uncer-
tainty.and.have.conflicting.objectives..The.various.stakeholders.with.an.interest.in.the. decision.are.likely.to.hold.many.different.perspectives..Scenarios.can.address.these. aspects.of.a.decision.problem. A. scenario. is. literally. an. outline. or. synopsis. of. a. play.. Scenarios. can. be. used.
to.describe.the.present.or. the.past..They.are.most.often.used.to.describe.possible. futures. Risk. scenarios. are. readily. used. to. provide. the. answers. to. our. four. informal.
questions:
