SCOPE uses Tree Hierarchies as a means of modelling the functional requirements of the software. Hierarchies are a powerful organisational technique to break large problems down into manageable tasks. The human race itself is a hierarchy; we have parents, grandparents, great-grandparents, and so on, in an extended hierarchy that graphically describes our inter-relationships and forms our family trees.
Whenever we face the need to introduce a system of classification to describe relationships, it is the hierarchy that we naturally choose. Phylum, class, order, etc. for plants and animals, Dewey decimal notation for library books, domain names on the Internet, directory classifications in Microsoft® Windows Explorer; these are all examples of hierarchical arrangements.
Hierarchies are powerful precisely because they are natural to us. They enable us to get around our built-in limitations and sort complex information in a structured and comprehensible manner.
SCOPE supports this natural way of thinking by visually arranging information in a way that makes sense. It reduces hundreds of pages of functional specifications to a graphical model that can be used to quickly communicate and negotiate software content and project scope with the business user.
See also Types of Hierarchy Trees in SCOPE.