Scenario-Based Development and Verification of Domain-Specific Languages

The use of domain-specific languages (DSLs) has increased manifold for problem solving in specific domain areas as they allow for a wider variety of expressions within their domain. Modeling using DSLs has shown high increases in productivity after accounting for the time and cost expended in developing them, making them a suitable target for improvement in order to reap higher rewards. The currently used approach for domain modeling involves the creation of an ontology which is then used to describe the domain model. This ontology encapsulates all domain knowledge and can be cumbersome to create, requiring external sources of information and assistance from a domain expert. This dissertation first discusses the use and importance of DSLs for scenario generation for a domain and presents an extension to the Aviation Scenario Definition Language (ASDL). The main contribution of this dissertation is a novel framework for scenario based development of DSLs, called the Domain-Specific Scenario (DoSS) framework. This framework proposes the use of scenarios in natural language, which are currently used in requirements engineering and testing, as the basis for developing the domain model iteratively. An example of the use of this approach is provided by developing a domain model for ASDL and comparing the published model with one obtained using DoSS. This approach is supplemented with a case study to validate the claim that DoSS is easier to use by non-experts in the domain by having a user create a model and comparing it to one obtained by the author. These models were found to be almost identical, showing a promising return for this approach. The time taken and effort required to create this model by the user were recorded and found to be quite low, although no similar results have been published so no comparison could be made. State charts are then used for verification of scenarios to ensure the conformity between scenarios and models. The dissertation also discusses applications of the ideas presented here, specifically, the use of ASDL for Air Traffic Control training scenarios and the use of DoSS for ontology generation

A Technique for Visualizing Software Architectures

Software architecture appeared in the early 1990s as a distinct discipline within software engineering. Models based on software architecture attempt to reduce the complexity of software by providing relatively coarse-grained structures for representing different aspects of software development. A software architecture typically consists of various components and connections arranged in a specific topology. Elements of the topology can serve as abstractions on (for example) modules, objects, protocols or interfaces. The meaning of the topology depends on viewpoint. Software architectures\u27 can be described using an architecture description language (ADL). The key goals of ADLs are to communicate alternate designs to the different individuals involved in software development (such individuals are referred to as stakeholders ), to detect reusable structures, and to record design decisions. A major problem in software architecture has been the difficulty of creating different representations of an architecture to accommodate differing viewpoints of stakeholders. Ideally, different viewpoints would be conveyed in a way that is both comprehensive enough for specialists but consistent enough for generalists. The representation problem has been one of reconciling and integrating different viewpoints. This dissertation provided a solution to the representation problem by creating a tool for three-dimensional visualization of software architectures using the Virtual Reality Modeling Language (VRML). Different architectural viewpoints were first defined in an ADL called the Visually Translatable Architecture Description Language (VT ADL). When VT ADL was translated into VRML, software architectures were embodied within three-dimensional worlds through which stakeholders may navigate. Each viewpoint was a separate VRML world. A viewpoint could be related to other viewpoints, representing different facets of software architectures, to reflect different stakeholder requirements. Traceability from design to requirements was possible through VRML hyperlinks from the visualized architecture. The goal of the dissertation was to develop a prototype for demonstrating the visualization technique. Based on the successful results of two visualization case studies, we concluded that the goal was achieved. Refinement of the prototype into a polished visualization tool was recommended. In future research, the refined version should be used for realistic evaluation of the technique in an actual software development environment

First International Conference on Ada (R) Programming Language Applications for the NASA Space Station, volume 2

Topics discussed include: reusability; mission critical issues; run time; expert systems; language issues; life cycle issues; software tools; and computers for Ada