SPICES Publications

Abstract
In recent trends, the Architecture Analysis and Design Language (AADL) has received increasing attention from safety-critical software development industries. Specific about the AADL is its strong syntactic and semantic support for the description of both hardware and software architectures. Considering the existing range of software architectures, we study the support AADL offers for the description of software architecture. As a case study we use an implementation of a UDP/IP protocol stack. Based on our experiences, our position is that a number of abstract concepts, e.g. a generic component concept, are missing in the AADL to make it well-suited for the highlevel description of software architecture.

Abstract
On today's sharply competitive industrial market, engineers must focus on their core competencies to produce ever more innovative products, while also reducing development times and costs. This has further heightened the complexity of the development process. At the same time, industrial systems, and specifically real-time embedded systems, have become increasingly software-intensive. New software development approaches and methods must therefore be found to free engineers from the even more complex technical constraints of development and to enable them to concentrate on their core business specialties. One emerging solution is to foster model-based development by defining modeling artifacts well-suited to their domain concerns instead of asking them to write code. However, model-driven approaches will be solutions to the previous issues only if models evolves from a contemplative role to a productive role within the development processes. In this context, model transformation is a key design paradigm that will foster this revolution. This paper is the result of discussions and exchanges that took place within the second edition of the workshop 'UML and AADL' (http://www.artist-embedded.org/artist/Topics.html) that was held in 2007 in Auckland, New Zealand, in conjunction with the ICECCS07 conference. The purpose of this workshop was to gather people of both communities from UML (including its domain specific extensions, with a focus on MARTE) and AADL (including its annexes) in order to foster sharing of results and experiments. More specially this year, the focus was on how both standards do subscribe to the model driven engineering paradigm, or to be more precise, how MDE may ease and foster the usage of both sets of standards for developing real-time embedded systems. This paper will show that, even if the work is not yet finished, the current results seems to be already very promising.

Abstract
SPICES AADL Modelling and Analysis, SPICES Component Framework

Abstract
In this paper, we study a mapping from AADL to Java-RTSJ. After reviewing the basic concepts of the AADL execution model, we present the basic notions of Java-RTSJ, we rely on, for our mapping. Then, we propose a mapping taking into account a given subset of AADL. A related works section reviews existing works and elaborates on some comparisons.

Abstract
In this paper, we present an evaluation of the AADL Behavioural Annex that is currently in evaluation phase. We relate our experiment with respect to a development concerning the reengineering of a flight software. This experiments has led us to introduce hierarchical aspects and study the link especially with AADL modes. We discuss about the definition of a semantics for the AADL execution model and propose some enhancements.

Abstract
Software-intensive systems require the verification of functional and non-functional properties before the implementation and integration phases of the development process. In recent trends, the Architecture Analysis and Design Language (AADL) has proven a good candidate as a modeling language for softwareintensive systems. At the same time, Model Driven Development (MDD) is gaining popularity as a development process. In this paper, we explore the use of AADL in a model driven development process from a usability point of view. Three issues regarding the usability of AADL as a modeling language for softwareintensive systems are identified, namely system versus software level, complex component composition and property ambiguity. For resolving these issues, an approach is presented through integration of AADL models in a model driven development process with specifically designed model transformations. This approach enhances the usability of AADL for software developers.

Abstract
Due to the increasing complexity of embedded systems, new design methodologies have to be adopted, since traditional techniques are no longer efficient. Model-based engineering enables the designer to confront these concerns using the architecture description of the system as the main axis during the design cycle. Defining the architecture of the system before its implementation, enables the analysis of the constraints imposed on the system from the beginning of the design cycle until the final implementation. AADL has been proposed to design and analyze software and hardware architectures for real time, mission-critical, embedded systems. In this paper, the specification for modelling AADL by means of SystemC is provided. The SystemC model will enable the refinement of the AADL specification until the final implementation is developed. The information about the system obtained during the refinement process will feedback the AADL model allowing the verification of high-level constraints during the complete design process.

Abstract
The development process of distributed real-time embedded systems (DRES) suffers significant limitations when addressing the antagonistic concerns of systems interoperability, flexibility, and reliability. In this paper, we first present a component-based development process and related architecture designed to enable DRES interoperability while improving developer productivity. We then describe the techniques this process uses in order to improve reliability of these systems. The component-based framework is illustrated by a practical use case. Lastly, we present research orientations addressing verification, validation, and certifiability on the one hand, and their ability to tackle with the always-growing flexibility requirements on the other hand.

Abstract
In a real-time system architecture, the notion of a bus component plays an important role as it forms the backbone of communication among all the devices of the system. For this purpose, we need a precise specification of buses for applications that will run on top of them and for developers who implement device protocols. In this paper, we propose an incremental methodology to elaborate detailed bus protocol descriptions that may be useful in both design and temporal property verification, by specifying a protocol from a simple representation to a complete one by means of successive refinements, thus also permitting the refinement of model properties. The methodology is then tested with AADL and TLA specifications of the PCI bus protocol.

Abstract
Developing a model-based approach Supporting mission-critical embedded systems. Several industries are currently facing the issue of developing mission-critical embedded computer-based systems with increasing complexity, dependability and economic pressures such as cost and time to market. Model-driven development/ engineering (MDD/MDE) addresses those issues. Today, sectors such as aerospace, automotive and communications are rather segmented and are prone to study and promote dedicated solutions, whereas cross-fertilisation would be more beneficial. SPICES will implement an integrated MDD/MDE methodology for designing, verifying and implementing avionics mission-critical real-time embedded (RT/E) systems.