scope:

Computer-Aided Software Engineering (CASE) tools are used to describe the behavior of software using a variety of different design notations. These may be graphical or textual in nature, or they may be a combination. This standard provides a reference model of fundamental software concepts that form the "building blocks" for a number of these commonly used notations. This standard also includes a textual language, the Semantic Transfer Language (STL), for representing software application behavior descriptions. A software behavior description consists of a collection of sentences that conform to the formal syntax of the STL and that are to be interpreted in terms of the software concepts defined in this standard. The STL syntax is designed to be computer-parsable, while remaining easy for users to read and write. This reference model and transfer syntax may be used for directly recording, storing, and analyzing a software behavior description, as well as for transferring elements of a software behavior description between CASE tools.

This standard excludes the structural descriptions of software product designs or implementations, and it does not provide a traceable decomposition of software into programs, modules, subroutines, or objects. However, it does provide the means to describe the functions and behavior of a program, module, subroutine, or object.

This standard focuses on the semantics of information concerning software behavior, not on graphical representations for that information. Graphical information is not important when communicating among tools that do not need to reproduce the same drawing. However, the STL defined in this standard does include references to images or drawings of graphical symbols that may be used to indicate correspondences between graphical and textual representations of the same software concepts.