Séverine Sentilles

A Classification Framework for Software Component Models

In the last decade, a large number of different software component models have been developed, with different aims and using different principles and technologies. This has resulted in a number of models which have many similarities, but also principal differences, and in many cases unclear concepts. Component-based development has not succeeded in providing standard principles, as has, for example, object-oriented development. In order to increase the understanding of the concepts and to differentiate component models more easily, this paper identifies, discusses, and characterizes fundamental principles of component models and provides a Component Model Classification Framework based on these principles. Further, the paper classifies a large number of component models using this framework.

A Component Model for Control-Intensive Distributed Embedded Systems

In this paper we focus on design of a class of distributed embedded systems that primarily perform real-time controlling tasks. We propose a two-layer component model for design and development of such embedded systems with the aim of using component-based development for decreasing the complexity in design and providing a ground for analyzing them and predict their properties, such as resource consumption and timing behavior. The two-layer model is used to efficiently cope with different design paradigms on different abstraction levels. The model is illustrated by an example from the vehicular domain.

Integration of Extra-Functional Properties in Component Models

Management of extra-functional properties in component models is one of the main challenges in the component-based software engineering community. Still, the starting point in their management, namely their specification in a context of component models is not addressed in a systematic way. Extra-functional properties can be expressed as attributes (or combinations of them) of components, or of a system, but also as attributes of other elements, such as interfaces and connectors. Attributes can be defined as estimations, or can be measured, or modelled; this means that an attribute can be expressed through multiple values valid under different conditions. This paper addresses how this diversity in attribute specifications and their relations to component model can be expressed, by proposing a model for attribute specifications and their integrations in component models. A format for attribute specification is proposed, discussed and analyzed, and the approach is exemplified through its integration both in the ProCom component model and its integrated development environment.

A Component Model Family for Vehicular Embedded Systems

In this paper we propose to use components for managing the increasing complexity in modern vehicular systems. Compared to other approaches, the distinguishing feature of our work is using and benefiting from components throughout the development process from early design to development and deployment, and an explicit separation of concerns at different levels of granularity. Based on the elaboration of the specifics of vehicular systems (resource constraints, real-time requirements, hard demands on reliability), the paper identifies concerns that need to be addressed by a component model for this domain, and describes a realization of such a component model.

Save-IDE - A tool for design, analysis and implementation of component-based embedded systems

The paper presents Save-IDE, an Integrated Development Environment for the development of component-based embedded systems. Save-IDE supports efficient development of dependable embedded systems by providing tools for design of embedded software systems using a dedicated component model, formal specification and analysis of component and system behaviors already in early development phases, and a fully automated transformation of the system of components into an executable image.

Save-IDE: An Integrated Development Environment for Building Predictable Component-Based Embedded Systems

In this paper we present an Integrated Development Environment Save-IDE, a toolset that embraces several tools: a tool for designing component-based systems and components, modeling and predicting certain run-time properties, such as timing properties, and transforming the components to real-time execution elements. Save-IDE is specialized for the domain of dependable embedded systems, which in addition to standard design tools requires tool support for analysis and verification of particular properties of such systems.

Evolution management of extra-functional properties in component-based embedded systems

As software complexity increases in embedded systems domain, component-based development becomes increasingly attractive. A main challenge in this approach is however to analyze the systems extra-functional properties (such as timing properties, or resource requirements), an important step in a development of embedded systems. Analysis of such properties are computational and time consuming, and often difficult. For this reason reuse of the results of the analysis is as important as the reuse of the component itself, especially in case of modifications of the context in which the component is used. This paper presents concepts and mechanisms that allow to automatically discover whether a property value is still valid when related components evolve: a value context language is proposed to formally define the validity conditions and identify possible threats.

Flexible Semantic-Preserving Flattening of Hierarchical Component Models

Hierarchical component models allow to better manage system design complexity compared to flat component models. However, many analysis techniques lack support for dealing with hierarchical models. This paper presents a general approach to use existing analysis on hierarchical component systems by means of a flattening transformation. The transformation can be partially applied, which provides a possibility for tradeoffs between analysis scalability, result precision and reusability concerns. The general approach has been implemented and evaluated in the context of ProCom, a hierarchical component model for real-time embedded systems. As a result, the paper describes a flattening transformation which preserves the ProCom operational semantics and presents the related optimizations.

Integrating Behavioral Descriptions into a Component Model for Embedded Systems

When component-based development is applied to distributed embedded systems, which are often safety-critical and subject to real-time constraints, it is of significant importance that reliable predictions of functional and extra functional properties can be derived at design-time. Preferably, analysis should be performed in early development phases, where the cost of modifying the design is lower. Centered on an example application from the automation domain, we show how a component model specifically intended for embedded systems can be combined with a language for high-level formal behavior modeling. This permits analysis of system properties, while also supporting reuse of behavioral models when components are reused.

Decision support for choosing architectural assets in the development of software-intensive systems: The GRADE taxonomy

Engineering software-intensive systems is a complex process that typically involves making many critical decisions. A continuous challenge during system design, analysis and development is deciding on the reference architecture that could reduce risks and deliver the expected functionality and quality of a product or a service to its users. The lack of evidence in documenting strategies supporting decision-making in the selection of architectural assets in systems and software engineering creates an impediment in learning, improving and also reducing the risks involved. In order to fill this gap, ten experienced researchers in the field of decision support for the selection of architectural assets in engineering software-intensive systems conducted a workshop to reduce traceability of strategies and define a dedicated taxonomy. The result was the GRADE taxonomy, whose key elements can be used to support decision-making as exemplified through a real case instantiation for validation purposes. The overall aim is to support future work of researchers and practitioners in decision-making in the context of architectural assets in the development of software-intensive systems. The taxonomy may be used in three ways: (i) identify new opportunities in structuring decisions; (ii) support the review of alternatives and enable informed decisions; and (iii) evaluate decisions by describing in a retrospective fashion decisions, factors impacting the decision and the outcome.