ITS provides tools to support four application development roles: an application expert, a style expert, an application programmer, and a style programmer. ITS supports each role by an appropriate set of software tools. Using these tools application and style experts directly create executable parts of a system.

An application expert is familiar with some problem domain such as the airline industry and wants to implement a computer application in that domain. The application expert typically is not trained in programming, nor is part of an information systems department. Traditionally the application expert interacts with a systems analyst to produce a design specification. Later, the specification would be implemented by application programmers. Application designs produced by the analyst are not executable, but usually are represented as natural language or pseudo code algorithms. These incomplete specifications create opportunities for costly design errors. ITS provides tools to allow application experts to create executable specifications to reduce misunderstandings with programmers, and to decrease the time required to create successive prototypes of a system.

The style expert similarly has had relatively poor tool support in traditional application development. A style expert may be a graphic artist or human factors engineer. Human factors experts in the past have worked as consultants in development projects drafting design guidelines or evaluating prototypes. They have had no separable work product, such as an executable style definition, and have had difficulty influencing designs indirectly through developers. Neither type of expert is assumed to be proficient in...