Mathieu Acher

Automating the formalization of product comparison matrices

Product Comparison Matrices (PCMs) form a rich source of data for comparing a set of related and competing products over numerous features. Despite their apparent simplicity, PCMs contain heterogeneous, ambiguous, uncontrolled and partial information that hinders their efficient exploitations. In this paper, we formalize PCMs through model-based automated techniques and develop additional tooling to support the edition and re-engineering of PCMs. 20 participants used our editor to evaluate the PCM metamodel and automated transformations. The results over 75 PCMs from Wikipedia show that (1) a significant proportion of the formalization of PCMs can be automated -- 93.11% of the 30061 cells are correctly formalized; (2) the rest of the formalization can be realized by using the editor and mapping cells to existing concepts of the metamodel. The automated approach opens avenues for engaging a community in the mining, re-engineering, edition, and exploitation of PCMs that now abound on the Internet.

ATSyRa: An Integrated Environment for Synthesizing Attack Trees

Attack trees are widely considered in the fields of security for the analysis of risks (or threats) against electronics, computer control, or physical systems. A major barrier is that attack trees can become largely complex and thus hard to specify. This paper presents ATSyRA, a tooling environment to automatically synthesize attack trees of a system under study. ATSyRA provides advanced editors to specify high-level descriptions of a system, high-level actions to structure the tree, and ways to interactively refine the synthesis. We illustrate how users can specify a military building, abstract and organize attacks, and eventually obtain a readable attack tree.

Towards managing variability in the safety design of an automotive hall effect sensor

This paper discusses the merits and challenges of adopting software product line engineering (SPLE) as the main development process for an automotive Hall Effect sensor. This versatile component is integrated into a number of automotive applications with varying safety requirements (e.g., windshield wipers and brake pedals). This paper provides a detailed explanation as to why the process of safety assessment and verification of the Hall Effect sensor is currently cumbersome and repetitive: it must be repeated entirely for every automotive application in which the sensor is to be used. In addition, no support is given to the engineer to select and configure the appropriate safety solutions and to explain the safety implications of his decisions. To address these problems, we present a tailored SPLE-based approach that combines model-driven development with advanced model composition techniques for applying and reasoning about specific safety solutions. In addition, we provide insights about how this approach can reduce the overall complexity, improve reusability, and facilitate safety assessment of the Hall Effect sensor.

Generating counterexamples of model-based software product lines

In a model-based software product line (MSPL), the variability of the domain is characterized in a variability model and the core artifacts are base models conforming to a modeling language (also called metamodel). A realization model connects the features of the variability model to the base model elements, triggering operations over these elements based on a configuration. The design space of an MSPL is extremely complex to manage for the engineer, since the number of variants may be exponential and the derived product models have to be conforming to numerous well-formedness and business rules. In this paper, the objective is to provide a way to generate MSPLs, called counterexamples (also called antipatterns), that can produce invalid product models despite a valid configuration in the variability model. We describe the foundations and motivate the usefulness of counterexamples (e.g., inference of guidelines or domain-specific rules to avoid earlier the specification of incorrect mappings; testing oracles for increasing the robustness of derivation engines given a modeling language). We provide a generic process, based on the common variability language (CVL) to randomly search the space of MSPLs for a specific modeling language. We develop LineGen a tool on top of CVL and modeling technologies to support the methodology and the process. LineGen targets different scenarios and is flexible to work either with just a domain metamodel as input or also with pre-defined variability models and base models. We validate the effectiveness of this process for three formalisms at different scales (up to 247 metaclasses and 684 rules). We also apply the approach in the context of a real industrial scenario involving a large-scale metamodel.

Deriving Usage Model Variants for Model-Based Testing: An Industrial Case Study

The strong cost pressure of the market and safety issues faced by aerospace industry affect the development. Suppliers are forced to continuously optimize their life-cycle processes to facilitate the development of variants for different customers and shorten time to market. Additionally, industrial safety standards like RTCA/DO-178C require high efforts for testing single products. A suitably organized test process for Product Lines (PL) can meet standards. In this paper, we propose an approach that adopts Model-based Testing (MBT) for PL. Usage models, a widely used MBT formalism that provides automatic test case generation capabilities, are equipped with variability information such that usage model variants can be derived for a given set of features. The approach is integrated in the professional MBT tool MaTeLo. We report on our experience gained from an industrial case study in the aerospace domain.

Assessing product line derivation operators applied to Java source code: an empirical study

Product Derivation is a key activity in Software Product Line Engineering. During this process, derivation operators modify or create core assets (e.g., model elements, source code instructions, components) by adding, removing or substituting them according to a given configuration. The result is a derived product that generally needs to conform to a programming or modeling language. Some operators lead to invalid products when applied to certain assets, some others do not; knowing this in advance can help to better use them, however this is challenging, specially if we consider assets expressed in extensive and complex languages such as Java. In this paper, we empirically answer the following question: which product line operators, applied to which program elements, can synthesize variants of programs that are incorrect, correct or perhaps even conforming to test suites? We implement source code transformations, based on the derivation operators of the Common Variability Language. We automatically synthesize more than 370,000 program variants from a set of 8 real large Java projects (up to 85,000 lines of code), obtaining an extensive panorama of the sanity of the operations.

Third International Workshop on Reverse Variability Engineering (REVE 2015), associated with SPLC

Variability management of a product family is the core aspect of Software Product Line Engineering. The adoption of this mature approach requires a high upfront investment before being able to automatically generate product instances based on customer requirements. However, this adoption costs and risks could be reduced with an incremental approach, which mines existing assets and then transitions to full product line engineering. Those existing assets can be for instance similar product variants that were implemented using ad-hoc reuse techniques such as clone-and-own. Hence, there is a great need of bottom-up approaches that extract variability from the artifacts (across all the life cycle) of the legacy product variants and manage the consolidated variability. The REVE workshop series aims to bring together the Reengineering and Software Product Line Engineering communities to address this gap.

Using fuzzy modeling for consistent definitions of product qualities in requirements

Companies increasingly rely on product differentiation and personalization strategies to provide their customers with an expansive catalog, and tools to assist them in finding the product meeting their needs. These tools include product search facilities, recommender systems, and product configurators. They typically represent a product as a set of features, which refer to a large number of technical specifications (e.g. size, weight, battery life). However, customers usually communicate and reason about products in terms of their qualities (e.g. ease-of-use, portability, ergonomics). In this paper, we tackle the problem of formalizing product qualities in the requirements of product-centred applications. Our goal is to extract product qualities from their technical features, so that customers can better perceive and evaluate the proposed products. To this end, we design a procedure for identifying segments of textual product documentation related to specific product qualities, and propose an approach based on fuzzy modeling to represent product qualities on top of technical specifications. Preliminary experiments we carried out on a catalog of cameras tend to show that fuzzy modeling is an appropriate formalism for representing product qualities. We also illustrate how modeled qualities can support the design of product configurators that are centered on the customers needs.

VaryLATEX: Learning Paper Variants That Meet Constraints

How to submit a research paper, a technical report, a grant proposal, or a curriculum vitae that respect imposed constraints such as formatting instructions and page limits? It is a challenging task, especially when coping with time pressure. In this work, we present VaryLATEX, a solution based on variability, constraint programming, and machine learning techniques for documents written in LATEX to meet constraints and deliver on time. Users simply have to annotate LATEX source files with variability information, e.g., (de)activating portions of text, tuning figures sizes, or tweaking line spacing. Then, a fully automated procedure learns constraints among Boolean and numerical values for avoiding non-acceptable paper variants, and finally, users can further configure their papers (e.g., aesthetic considerations) or pick a (random) paper variant that meets constraints, e.g., page limits. We describe our implementation and report the results of two experiences with VaryLATEX.

Teaching software product lines: a snapshot of current practices and challenges (journal-first abstract)

This extended abstract summarizes our article entitled Teaching Software Product Lines: A Snapshot of Current Practices and Challenges published in the ACM Transactions on Computing Education, vol. 18 in 2017 (http://doi.acm.org/10.1145/3088440). The article reports on three initiatives we have conducted with scholars, educators, industry practitioners, and students to understand the connection between software product lines and education and to derive recommendations for educators to continue improving the state of practice of teaching SPLs.