Attribute—An attribute is a fundamental property of an object and is often a single numeric quantity. For example, the attributes of a pipe include diameter, length, and roughness.
Alternative—An alternative holds a family of related attributes so pieces of data that you are most likely to change together are grouped for easy referencing and editing. For example, a physical properties alternative groups physical data for the network's elements, such as elevations, sizes, and roughness coefficients.
Scenario—A scenario has a list of referenced alternatives (which hold the attributes) and combines these alternatives to form an overall set of system conditions that can be analyzed. This referencing of alternatives enables you to easily generate system conditions that mix and match groups of data that have been previously created. Scenarios do not actually hold any attribute data—the referenced alternatives do.
