Ada’s expressiveness, as well as the maturity of Ada-related methods and their potential for a high degree of standardization, affords special opportunities for the development of computer-aided software engineering (CASE) tools. Tools that provide automated uses of graphics in software development form one of the most important categories of CASE. This paper is structured around the presentation of such a tool and portrays various aspects of the tool’s motivation, conceptual foundations, and operation. A discussion of a CASE tool’s capabilities must be additionally concerned with the methodology supported by the tool and the graphical notations associated with that methodology. The methodology supported by SKETCHER is object-oriented, and its graphics are based on the notational schemes of Booch and Buhr. (Although these topics are touched upon in the paper, they are not explored in depth.)

A paper of this nature may be of interest on several counts. For example, in order of increasing generality, it can portray the underlying rationale for and capabilities of a particular tool; it can reflect software development practices in widespread use within the Ada community; it can reveal general problems related to software methodology, graphics, and automation; and it can point the way to some useful solutions to these problems.

This paper begins by providing some useful background remarks regarding the use of Ada-specific graphics in software design and the ways in which use of an automated graphical tool can be of value. The major sections are concerned with the design criteria that shaped SKETCHER’s development, some aspects of the tool’s architecture and user interface, and, most of all, the tool’s method of operation. These sections provide a fair amount of detail and include a simple design example with illustrations. A section on “Lessons Learned” and a summary section give some insights into the nature of the benefits that have been gained from the tool’s use.

The content of this paper is weighted toward the more particular rather than the more general. It gives a clear description of the tool under discussion. A readable exposure to some of the mainstream issues involved in the use of Ada-specific methodologies and graphics, and an explanation of some of the benefits that can be realized by their automation, are also provided. The paper tends to present only the positive aspects of the tool’s use, however, and fails to address the more difficult issues, such as integration of the tool with other tools of the environment; integration of the methodology employed with those of other life cycle phases; and maintenance of consistency between the graphical representations produced by SKETCHER and textual (PDL or Ada source) representations as they evolve through later stages of the design process.