Abstract-The design of fault-tolerant automation systems is a complex task. These systems must not only satisfy real-time requirements but they must also deliver the specified functionality in the presence of both software and hardware faults. To achieve fault-tolerance, systems have to use redundancy. This redundancy is usually achieved by replicating hardware units and executing the application within a distributed system.Model-based design tools promise to reduce the complexity of the design process by raising the abstraction level. However, most of the existing tools focus only on functional aspects. Code realizing extra-functional requirements such as fault-tolerance mechanisms, communication, and scheduling is not targeted. However, this type of code makes up the majority of the code of a fault-tolerant real-time system. This paper presents FTOS, a model-based development tool for the design of fault-tolerant automation systems that focuses on code generation of extrafunctional requirements and therefore complements existing tools.

Safety standards, such as IEC 61508, play an important role in assuring the safety of embedded systems. Since model-driven development (MDD) is also gaining importance in the development process of these systems, an integration of the standards with existing modeling theory is promising. However, one of the basic building blocks of MDD, the metamodels, have not been made "standard-aware" yet. This paper presents a first step of such an integration by using a standard-aware metamodel to synthesize diagnostic techniques. This is an important task, because the correct selection and implementation of these techniques is traditionally a manual, labor-intensive task. The necessary steps of such an integration are discussed, including the definition of the metamodel, the formulation of an algorithm to select the right diagnostic techniques, and the implementation of code generation.

Safety requirements are an important artifact in the development of safety critical systems. They are used by experts as a basis for appropriate selection and implementation of fault detection mechanisms. Various research groups have worked on their formal modeling with the goal of determining if a system can meet these requirements.In this paper, we propose the application of formal models of safety requirements throughout all constructive development phases of a model-driven development process to automatically generate appropriate fault detection mechanisms. The main contribution of this paper is a rigorous formal specification of safety requirements that allows the automatic propagation, transformation and refinement of safety requirements and the derivation of appropriate fault detection mechanisms. This is an important step to guarantee consistency and completeness in the critical transition from requirements engineering to software design, where a lot of errors can be introduced into a system by using conventional, non-formal techniques.

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Safety requirements are an important artifact in the development of safety critical systems. They are used by experts as a basis for appropriate selection and implementation of fault detection mechanisms. Various research groups have worked on their formal modeling with the goal of determining if a system can meet these requirements.In this paper, we propose the application of formal models of safety requirements throughout all constructive development phases of a model-driven development process to automatically generate appropriate fault detection mechanisms. The main contribution of this paper is a rigorous formal specification of safety requirements that allows the automatic propagation, transformation and refinement of safety requirements and the derivation of appropriate fault detection mechanisms. This is an important step to guarantee consistency and completeness in the critical transition from requirements engineering to software design, where a lot of errors can be introduced into a system by using conventional, non-formal techniques.