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Avionics systems are complex systems that integrate hardware, communication media, have many interactions with other subsystems, within or outside of the aircraft, and for the system discussed in this presentation, integrate software that must be developed according to DO-178B guidelines. System engineering and software engineering are two engineering disciplines that are historically handled by teams with different cultures, and when their engineering processes are supported by tools, use different and incompatible tools. This often leads to a difficult collaboration, with at some point, redundant information and inconsistencies. This presentation introduces a solution, based on the SysML standard for system modeling, and on the SCADE Suite product from Esterel Technologies for the development of DO-178B certified software components.

The increasing complexity of distributed embedded systems, as found today in airplanes or cars, becomes more and more a critical cost-factor for their development. Model-based approaches have recently demonstrated their potential for both improving and accelerating (software) development processes. Therefore, in the project DECOS1, which aims at improving system architectures and development of distributed safety-critical embedded systems, an integrated, model-driven tool-chain is established, accompanying the system development process from design to deployment. This paper gives an overview of this tool-chain and outlines important design decisions and features.

Development and verification of systems for internal aircraft networks include multiple software layers. These layers are mainly the application-specific components, communication layers, redundancy management and other system services. Verification of these system layers in the early stages of the design process, before a physical network is available, and during the design process has become a critical need in order to reduce design costs and project risks. Time-Triggered Architectures (TTA) and SCADE are both well-established technologies and tools for building safety-critical embedded systems. Both are based on the synchronous paradigm; TTA for the communication infrastructure and distributed embedded computing, and SCADE for simulating and generating code for the application components.

In this paper we will explore how 15 years after being introduced into avionics systems, “by-wire” technologies have entered the automotive world. The use of software within safety-relevant application areas like restraint systems, braking, steering and vehicle dynamics support and control systems, is requiring changes in the processes and methodologies used for embedded software development.

The ARINC 661 standard [1] defines a Cockpit Display System (CDS) interface intended for all types of aircrafts installations. This paper presents an integrated solution based on Commercial Off-The-Shelf (COTS) tools that allows, in the initial stage of an aircraft project, support for the expression of requirements with regards to the CDS definition and the CDS interaction with the User Applications (UAs). It also enables prototyping of the systems architecture from the point of view of functionalities and performance. At a later stage of the project, this same integrated tool suite can be used to produce and certify the final embedded software code within the CDS and to generate the communication code between the CDS and the UAs.

This paper presents the SCADE System™ product line for systems modeling and generation based on the SysML standard and the Eclipse Papyrus open source technology. SCADE System has been developed in the framework of Listerel, a joint laboratory of Esterel Technologies, provider of the SCADE® tools, and CEA LIST, project leader of the Eclipse component, Papyrus. From an architecture point of view, the Esterel SCADE tools are built on top of the SCADE platform which includes both SCADE Suite®, a model-based development environment dedicated to critical software, and SCADE System enabling model-based system engineering. SCADE System includes Papyrus, an open source component (under EPL license), integrated in the modeling platform of Eclipse. Using this integrated modeling platform, both system and software teams share the same environment for system development. Furthermore, other model-based tools can be added to the environment, due to the use of Eclipse.

This paper introduces a model-based systems and embedded software engineering, workflow for the design of control systems. The interdisciplinary approach that is presented relies on an integrated set of tools that addresses the needs of various engineering groups, including system architecture, design, and validation. For each of these groups, a set of best practices has been established and targeted tools are proposed and integrated in a unique platform, thus allowing efficient communication between the various groups. In the initial stages of system design, including functional and architectural design, a SysML-based approach is proposed. This solution is the basis to develop systems that have to obey both functional and certification standards such as ARINC 653 (IMA) and ARP 4754A. Detailed system design typically requires modeling and simulation of each individual physical component of the system by various engineering groups (mechanical, electrical, etc.).

Model Based System Engineering is considered today as the approach that can meet the continually growing complexity of avionics, a challenge that is compounded by constant market pressure (cost, time to market, need for product variants…) For each activity in the product life cycle, tools and technologies supporting an MBSE approach already exist, such as embedded code generation, formal safety analysis, electrical harness design; however, one of the greatest challenges consists in integrating these diverse system development tools into a global framework that ensures the consistency of perspectives and a seamless workflow across processes. Citrus is being developed as an open environment that targets the main activities of systems and software engineering: modeling and validating functions, allocating functional and non-functional requirements to systems, developing the physical architecture, interface design, allocating system requirements to software and hardware items.

The design of integrated modular avionics (IMA) for next-generation aircraft is a significant challenge for the industry in terms of complexity, time-to-market, certification and design effort. Because of those constraints, traditional hand-coding may no longer be a cost-effective option, especially for DO-178C Design Assurance Level (DAL) A Safety-critical applications. While the use of Commercial Off-The-Shelf (COTS) HMI-modeling tools could be a more efficient option, its introduction in an existing environment may result in high risk and effort. This paper presents the approach for the evaluation of the SCADE Display tool for a primary flight display (PFD) application. In this evaluation, a subset of a previously developed PFD was re-modeled with SCADE Display. The creation of the model served as an evaluation of the usability and the flexibility of the tool. The integration of the generated code on an existing platform was evaluated.

Formal verification is increasingly used for checking and proving the correctness of digital systems. In this paper, we present formal verification as a cost-effective technique for the verification and validation of model-based safety-critical embedded systems. We start by explaining how formal verification can be easily integrated in a model-based development methodology for critical embedded software. In the methodology examined, the development methods are based upon a formal and deterministic language representation and a correct-by-construction automatic code generation. In this methodology, formal verification proves that what you execute conforms to safety requirements, and what you execute is exactly what you embed. We show the impacts and benefits of using formal verification in software development that must be compliant with the IEC 61508 standards, especially for SIL 3 and SIL 4 software development.