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Modularity benefits, including the independent maintenance and comprehension of individual modules, have been widely advocated. However, empirical assessments to investigate those benefits have mostly focused on source code, and thus, the relevance of modularity to earlier artifacts is still not so clear (such as requirements and design models). In this paper, we use a multimethod technique, including designed experiments, to empirically evaluate the benefits of modularity in the context of two approaches for specifying product line use case scenarios: PLUSS and MSVCM. The first uses an annotative approach for specifying variability, whereas the second relies on aspect-oriented constructs for separating common and variant scenario specifications. After evaluating these approaches through the specifications of several systems, we find out that MSVCM reduces feature scattering and improves scenario cohesion. These results suggest that evolving a product line specification using MSVCM requires only localized changes. On the other hand, the results of six experiments reveal that MSVCM requires more time to derive the product line specifications and, contrasting with the modularity results, reduces the time to evolve a product line specification only when the subjects have been well trained and are used to the task of evolving product line specifications.

Context: To reduce the integration effort arising from conflicting changes resulting from collaborative software development tasks, unstructured merge tools try to automatically solve part of the conflicts via textual similarity, whereas structured and semistructured merge tools try to go further by exploiting the syntactic structure of the involved artifacts. Objective: In this study, aiming at increasing the existing body of evidence and assessing results for systems developed under an alternative version control paradigm, we replicate an experiment conducted by Apel et al. to compare the unstructured and semistructured approach with respect to the occurrence of conflicts reported by both approaches. Method: We used both semistructured and unstructured merge in a sample 2.5 times bigger than the original study regarding the number of projects and 18 times bigger regarding the number of merge scenarios, and we compared the occurrence of conflicts. Results: Similar to the original study, we observed that semistructured merge reduces the number of conflicts in 55% of the scenarios of the new sample. However, the observed average conflict reduction of 62% in these scenarios is far superior than what has been observed before. We also bring new evidence that the use of semistructured merge can reduce the occurrence of conflicting merge scenarios by half. Conclusions: Our findings reinforce the benefits of exploiting the syntactic structure of the artifacts involved in code integration. Besides, the reductions observed in the number and size of conflicts suggest that the use of semistructured merge, when compared to the unstructured approach, might decrease integration effort without compromising correctness.

International audience; Software 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.

This paper presents a process-oriented model-driven approach that supports the conduction of controlled experiments in software engineering. The approach consists of: (i) a domain specific language (DSL) for process specification and statistical design of controlled experiments; (ii) model-driven transformations that allow workflow models generations specific to each experiment participant and according to the experiment statistical design; and (iii) a workflow execution environment that allows the monitoring of participant activities in the experiment, besides gathering participants feedback from the experiment. The paper also presents the results of an exploratory study that analyzes the feasibility of the approach and the expressivity of the DSLs in the modeling of a non-trivial software engineering experiment.

SPL testing has been considered a challenging task,mainly due to the diversity of products that might be generatedfrom an SPL. To deal with this problem, some techniques for derivingproduct specific functional test cases have been proposed.However, this research area still lacks empirical studies showingthe benefits of using such techniques. This paper presents a studythat empirically compares two different black-box manual testdesign techniques: a generic technique that we have observed inan industrial test execution environment and a product specifictechnique whose functional test cases could be derived using anySPL technique that considers variations in functional tests. Weevaluated their impact from the point of view of the test execution process, achieving results that indicate that executing product specific test cases is faster and generates fewer errors.

In Brazil, a country of continental proportions, law requires that health institutions directly involved in the cancer treatment in the country have to register and consolidate cancer patients' data. This information is important for the management and evaluation of the cancer treatment, and for the definition of public policies. In this work we propose the use of a high-performance computational infrastructure, based on grid computing, to ease and accelerate the consolidation of the remotely distributed patients' records in these institutions. In particular, we present a case study of implementation of a tool for patients' survival estimation based on the Kaplan-Meier method. We also discuss the issues related to architecture, implementation and integration, as well as the benefits and prospects for the use of this infrastructure on the establishment of a national health information system.