VCU: The Three Dimensions of Reuse

Abstract

Abstract. Reuse, enabled by modularity and interfaces, is one of the most important concepts in software engineering. This is evidenced by an increasingly large number of reusable artifacts, ranging from small units such as classes to larger, more sophisticated units such as components, services, frameworks, software product lines, and concerns. This paper presents evidence that a canonical set of reuse interfaces has emerged over time: the variation, customization, and usage interfaces (VCU). A reusable artifact that provides all three interfaces reaches the highest potential of reuse, as it explicitly exposes how the artifact can be manipulated during the reuse process along these three dimensions. We demonstrate the wide applicability of the VCU interfaces along two axes: across abstraction layers of a system specification and across existing reuse techniques. The former is shown with the help of a comprehensive case study including reusable requirements, software, and hardware models for the authorization domain. The latter is shown with a discussion on how the VCU interfaces relate to existing reuse techniques.

Concern-oriented language development (COLD): Fostering reuse in language engineering

“…Artifacts are arranged in facets and perspectives to organize relationships between language constituents, languages, metalanguages, and language workbenches. COLD usage is organized around three language concern interfaces (variation, customization, usage), following principles already applied to general-purpose software development with concerns [11] . This enables systematic language (concern) reuse life cycles.…”

“…A concern provides a well-defined, three-part interface [11] . The Variation Interface (VI) of a concern is composed of a feature model [12] that expresses the closed variability 1 of solutions and techniques encapsulated within the concern by its designer, similar to what is done in software product lines for a specific application domain.…”

Concern-Oriented Use Cases.

“…A concern provides a well-defined, threepart interface (Kienzle et al 2016). The Variation Interface (VI) of a concern is composed of a feature model (Kang et al 1990) that expresses the closed variability (Svahnberg et al 2005) of solutions and techniques encapsulated within the concern by the concern designer, similar to what is done in SPLs for a specific application domain.…”

“…Typically, models for a system under development are created from scratch, rather than reusing already existing models. Modelling languages often lack explicit support for reuse, e.g., constructs for defining modules, interfaces, and composition (Herrmann et al 2007;Kienzle et al 2016), and there are very few libraries of reusable models available to developers. This is especially true for one of the most wide-spread modelling languages used to describe systems at a high level of abstraction during requirements elicitation: use cases (Jacobson et al 1992).…”