They are hypothetical outcomes or path dependent behavior for trading, hedging or analytical purposes.
Portrayals of alternative futures, usually in the form of written descriptions, but they could include graphs and illustrations. They may be broad, or focus on a particular aspect of life. They may often include a story of how that future came to develop, outlining anticipated key events, choices and consequences. A scenario would ideally also state its assumptions. Scenarios are sometimes well developed in Science Fiction.
Logical, compelling storylines of the future which serve to create alternative options.
Predictions of future events and outcomes based on techniques of decision science. Scenarios are often expressed as ‘risk profiles'—charts or tables that display the probability of an outcome occurring and its consequences.
"Short stories" that describe a system interaction with respect to some quality attribute. Typically, the focus would be on three kinds of scenarios: use case - anticipated uses of the system, growth - anticipated changes to the system, and exploratory - unanticipated stresses to the system (uses and/or changes).
Tracks of the key fiscal indicators based on long-run economic and fiscal assumptions. For example growth in expense categories reflects the sum of the change in the appropriate population cohort, inflation and a real growth factor (to reflect rising real wages and technology costs).