Combining SysML and AADL for the design, validation and implementation of critical systems

The realization of critical systems goes through multiple phases of specification, design, integration, validation, and testing. It starts from high-level sketches down to the final product. Model-Based Design has been acknowledged as a good conveyor to capture these steps. Yet, there is no universal solution to represent all activities. Two candidates are the OMG-based SysML to perform high-level modeling tasks, and the SAE AADL to perform lower-level ones, down to the implementation. The paper shares an experience on the seamless use of SysML and the AADL to model, validate/verify and implement a flight management system

Software dependability modeling using an industry-standard architecture description language

Performing dependability evaluation along with other analyses at architectural level allows both making architectural tradeoffs and predicting the effects of architectural decisions on the dependability of an application. This paper gives guidelines for building architectural dependability models for software systems using the AADL (Architecture Analysis and Design Language). It presents reusable modeling patterns for fault-tolerant applications and shows how the presented patterns can be used in the context of a subsystem of a real-life application

AADLib, A Library of Reusable AADL Models

The SAE Architecture Analysis and Design Language is now a well-established language for the description of critical embedded systems, but also cyber-physical ones. A wide range of analysis tools is already available, either as part of the OSATE tool chain, or separate ones. A key missing elements of AADL is a set of reusable building blocks to help learning AADL concepts, but also experiment already existing tool chains on validated real-life examples. In this paper, we present AADLib, a library of reusable model elements. AADLib is build on two pillars: 1/ a set of ready-to- use examples so that practitioners can learn more about the AADL language itself, but also experiment with existing tools. Each example comes with a full description of available analysis and expected results. This helps reducing the learning curve of the language. 2/ a set of reusable model elements that cover typical building blocks of critical systems: processors, networks, devices with a high level of fidelity so that the cost to start a new project is reduced. AADLib is distributed under a Free/Open Source License to further disseminate the AADL language. As such, AADLib provides a convenient way to discover AADL concepts and tool chains, and learn about its features

An architecture-based dependability modeling framework using AADL

For efficiency reasons, the software system designers' will is to use an integrated set of methods and tools to describe specifications and designs, and also to perform analyses such as dependability, schedulability and performance. AADL (Architecture Analysis and Design Language) has proved to be efficient for software architecture modeling. In addition, AADL was designed to accommodate several types of analyses. This paper presents an iterative dependency-driven approach for dependability modeling using AADL. It is illustrated on a small example. This approach is part of a complete framework that allows the generation of dependability analysis and evaluation models from AADL models to support the analysis of software and system architectures, in critical application domains

AADL for Cyber-Physical Systems: Semantics and beyond, validate what's next

The SAE Architecture Analysis and Design Language is a design-by-committee standard promoted to help the space and avionics domain. It now extends to a much broader audience, and this language is used in many domains related to Cyber-Physical Systems. AADL is an ADL promoted in the context of Model-Driven Engineering which has now gained a significant momentum in the industry. Models are a valuable asset that should be used and preserved down to the construction of the final system; modeling time and effort should be reduced to focus directly on the system and its realization. Yet, validation & verification may require many different analysis models, involving a strong theoretical background to be mastered. The SAE AADL has been defined to match the concepts understood by any engineer (interface, software or hardware components, packages, generics). From these concepts, typical behavior elements (scheduling and dispatch, communication mechanisms) have been added using both formal and informal description, always bound to theoretical frameworks for V&V. In parallel, the AADL allows one to attach user-defined properties or languages for specific analysis. This enables the application of many different techniques for the analysis of AADL models, among which schedulability, safety, security, fault-propagation, model-checking, resource dimensioning, etc.; but also code generation. In this talk, we give an overview of the AADL, and discuss how to use its features to analyse in depth a CPS case study

The TASTE Toolset: turning human designed heterogeneous systems into computer built homogeneous software.

The TASTE tool-set results from spin-off studies of the ASSERT project, which started in 2004 with the objective to propose innovative and pragmatic solutions to develop real-time software. One of the primary targets was satellite flight software, but it appeared quickly that their characteristics were shared among various embedded systems. The solutions that we developed now comprise a process and several tools ; the development process is based on the idea that real-time, embedded systems are heterogeneous by nature and that a unique UML-like language was not helping neither their construction, nor their validation. Rather than inventing yet another "ultimate" language, TASTE makes the link between existing and mature technologies such as Simulink, SDL, ASN.1, C, Ada, and generates complete, homogeneous software-based systems that one can straightforwardly download and execute on a physical target. Our current prototype is moving toward a marketed product, and sequel studies are already in place to support, among others, FPGA systems

Model based code generation for distributed embedded systems

Embedded systems are becoming increasingly complex and more distributed. Cost and quality requirements necessitate reuse of the functional software components for multiple deployment architectures. An important step is the allocation of software components to hardware. During this process the differences between the hardware and application software architectures must be reconciled. In this paper we discuss an architecture driven approach involving model-based techniques to resolve these differences and integrate hardware and software components. The system architecture serves as the underpinning based on which distributed real-time components can be generated. Generation of various embedded system architectures using the same functional architecture is discussed. The approach leverages the following technologies – IME (Integrated Modeling Environment), the SAE AADL (Architecture Analysis and Design Language), and Ocarina. The approach is illustrated using the electronic throttle control system as a case study

A MDE-based process for the design, implementation and validation of safety critical systems

Distributed Real-Time Embedded (DRE) systems have critical requirements that need to be verified. They are either related to functional (e.g. stability of a furnace controller) or non-functional (e.g. meeting deadlines) aspects. Model-Driven Engineering (MDE) tools have emerged to ease DRE systems design. These tools are also capable of generating code. However, these tools either focus on the functional aspects or on the runtime architecture. Hence, the development cycle is partitioned into pieces with heterogeneous modeling notations and poor coordination. In this paper, we propose a MDE-based process to create DRE systems without manual coding. We show how to integrate functional and architecture concerns in a unified process. We use industry-proven modeling languages to design functional elements of the system, and automatically integrate them using our AADL toolchain

Mapping AADL models to a repository of multiple schedulability analysis techniques

To fill the gap between the modeling of real-time systems and the scheduling analysis, we propose a framework that supports seamlessly the two aspects: 1) modeling a system using a methodology, in our case study, the Architecture Analysis and Design Language (AADL), and 2) helping to easily check temporal requirements (schedulability analysis, worst-case response time, sensitivity analysis, etc.). We introduce an intermediate framework called MoSaRT, which supports a rich semantic concerning temporal analysis. We show with a case study how the input model is transformed into a MoSaRT model, and how our framework is able to generate the proper models as inputs to several classic temporal analysis tools