Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Computer Science

First Advisor

Doris L. Carver


Object-oriented technology has opened the doors for many new ideas in system development. The object-oriented paradigm has produced many new object-oriented programming languages. As with any new methodology, a need for formalism arises to remove ambiguities and inconsistencies and to bring a sense of continuity to software design. Formal languages provide a sound basis for software development throughout the software life cycle. This work presents a set of characteristic features for object-oriented design languages and defines a formal object-oriented design language, DELTA. The rapidly changing face of software has led to an ever increasing need to update out-of-date methods and user interfaces. Software developers want to be able to use the same type of visual interfaces available in application software. The introduction of windowing environments has led to a market for methodologies which incorporate graphical features to supplement textual components of software. The present genre of formal languages must evolve in the same direction to be considered as effective in the design process. DELTA meets this need by providing a modern development environment with graphical features to complement the text that is necessary in any design specification. Researchers and prominent software engineers have provided a litany of object-oriented methodologies. The commonality of these methods is the step-by-step approach to software development. Software engineers agree in theory that the best approach to designing software which will stand the test of time is one which has a sound established discipline. Such a discipline produces a design in incrementations. DELTA supports this theory by providing established levels of incremental design representation. The advent of computer-aided design has led to the evolution of rapid-prototyping. Changes in system requirements, detection of errors, competition in the market, and the ongoing maintenance of software systems can be addressed by the development of system prototypes. DELTA responds to this challenge by establishing a design specification representation which can be easily mapped to an object-oriented programming language. This transition from design to prototype can be enhanced by formal annotations to the chosen implementation language. Annotations have been developed for DELTA software designs prototyped in the object-oriented language Actor.