Mauricio Alférez

VML* – a family of languages for variability management in software product lines

Managing variability is a challenging issue in software-product-line engineering. A key part of variability management is the ability to express explicitly the relationship between variability models (expressing the variability in the problem space, for example using feature models) and other artefacts of the product line, for example, requirements models and architecture models. Once these relations have been made explicit, they can be used for a number of purposes, most importantly for product derivation, but also for the generation of trace links or for checking the consistency of a product-line architecture. This paper bootstraps techniques from product-line engineering to produce a family of languages for variability management for easing the creation of new members of the family of languages. We show that developing such language families is feasible and demonstrate the flexibility of our language family by applying it to the development of two variability-management languages.

Relating feature models to other models of a software product line: a comparative study of featuremapper and VML

Software product lines using feature models often require the relation between feature models in problem space and the models used to describe the details of the product line to be expressed explicitly. This is particularly important, where automatic product derivation is required. Different approaches for modelling this mapping have been proposed in the literature. However, a discussion of their relative benefits and drawbacks is currently missing. As a first step towards a better understanding of this field, this paper applies two of these approaches-- FeatureMapper as a representative of declarative approaches and VML* as a representative of operational approaches--to the case study. We show in detail how the case study can be expressed using these approaches and discuss strengths and weaknesses of the two approaches with regard to the case study.

Multi-view composition language for software product line requirements

Composition of requirements models in Software Product Line (SPL) development enables stakeholders to derive the requirements of target software products and, very important, to reason about them. Given the growing complexity of SPL development and the various stakeholders involved, their requirements are often specified from heterogeneous, partial views. However, existing requirements composition languages are very limited to generate specific requirements views for SPL products. They do not provide specialized composition rules for referencing and composing elements in recurring requirements models, such as use cases and activity models. This paper presents a multi-view composition language for SPL requirements, the Variability Modeling Language for Requirements (VML4RE). This language describes how requirements elements expressed in different models should be composed to generate a specific SPL product. The use of VML4RE is illustrated with UML-based requirements models defined for a home automation SPL case study. The language is evaluated with additional case studies from different application domains, such as mobile phones and sales management.

Evaluating scenario-based SPL requirements approaches: the case for modularity, stability and expressiveness

AbstractSoftware product lines (SPL) provide support for productivity gains through systematic reuse. Among the various quality attributes supporting these goals, modularity, stability and expressiveness of feature specifications, their composition and configuration knowledge emerge as strategic values in modern software development paradigms. This paper presents a metric-based evaluation aiming at assessing how well the chosen qualities are supported by scenario-based SPL requirements approaches. The selected approaches for this study span from type of notation (textual or graphical based), style to support variability (annotation or composition based), and specification expressiveness. They are compared using the metrics developed in a set of releases from an exemplar case study. Our major findings indicate that composition-based approaches have greater potential to support modularity and stability, and that quantification mechanisms simplify and increase expressiveness of configuration knowledge and composition specifications.

Generating Requirements Analysis Models from Textual Requirements

Use case modeling is a commonly used technique to describe functional requirements in requirements engineering. Typically, use cases are captured from textual requirements documents describing the functionalities the system should meet. Requirements elicitation, analysis and modeling is a time consuming and error-prone activity, which it is not usually supported by automated tools. This paper tackles this problem by taking free-form textual requirements and offering a semi-automatic process for generation of domain models, such as use cases. Our goal is twofold: (i) reduce the time spent to produce requirements artifacts; and (ii) enable future application of model-driven engineering techniques to maintain traceability information and consistency between textual and requirements visual models artifacts.

Aspect-oriented model development at different levels of abstraction

The last decade has seen the development of diverse aspectoriented modeling (AOM) approaches. This paper presents eight different AOM approaches that produce models at different level of abstraction. The approaches are different with respect to the phases of the development lifecycle they target, and the support they provide for model composition and verification. The approaches are illustrated by models of the same concern from a case study to enable comparing of their expressive means. Understanding common elements and differences of approaches clarifies the role of aspect-orientation in the software development process.

Model-Driven Requirements Specification for Software Product Lines.

Model-driven methods for requirements specification in Software Product Lines (SPLs) support the construction of different models to provide a better understanding of each SPL feature and intended use scenarios. However, the different models must be composed to show the requirements of the target applications and, therefore, help to understand how features will be integrated in a new product of a software product line. Although well-established standards for creating metamodels and model transformations exist, there is currently no established foundation that allows practitioners to distinguish between the different modeling and composition approaches for requirements models. This chapter provides an overview of different approaches for specifying requirements models and composing models for specific products of an SPL. In particular, it emphasizes one of the most recurring specification techniques: model-driven and use case scenario-based specification. This technique, in combination with feature models and the Variability Modeling Language for Requirements (VML4RE), integrates our approach for model-driven requirements specification for SPLs.