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Auflistung nach Autor:in "Wasilewski, Michael"

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  • Konferenzbeitrag
    Defining requirements on domain-specific languages in model-driven software engineering of safety-critical systems
    (Software Engineering 2013 - Workshopband, 2013) Wasilewski, Michael; Hasselbring, Wilhelm; Nowotka, Dirk
    Domain-specific languages are designed and used to assist software development in various domains. Safety-critical systems such as aviation systems, railway control systems and nuclear power plants require certified software by law. This paper focuses on domain-specific languages that are used to represent a physical reality and to describe the behavior of a control software as a finite state machine. Furthermore we focus on domain-specific languages that are able to generate source code for sensor/actor systems from a specified finite state machine model. The source code is intended to be compiled and operated in a fixed time slot of a real-time operating system of a safety-critical controlling hardware. We give an example of a model that is expressed using a functional tree, a method that is based on input and state space partitioning. We show that models expressed by a functional tree are equivalent to deterministic and complete finite state machines. To formally prove the equivalence we analyze a model in terms of automata theory. We will furthermore show that omitting the properties of determinism and completeness violates normative requirements when a model is used to generate software for safetycritical systems. The major contribution of this paper is the definition of formal requirements on domain-specific languages employing formalisms of automata theory. The requirements are easily verifiable criteria for domain-specific languages to assess the suitability in an engineering process of a safety-critical system. We analyze two example modeling languages for their suitability to create a source code for safety-critical applications.
  • Konferenzbeitrag
    A formal and pragmatic approach to engineering safety-critical rail vehicle control software
    (Software Engineering 2011 – Fachtagung des GI-Fachbereichs Softwaretechnik, 2011) Wasilewski, Michael; Hasselbring, Wilhelm
    The engineering processes for safety-critical systems, for instance in the health care or transportation domains, are regulated by law. For software in the railroad industry in Europe the certification procedures have to obey the norm EN50128. This paper presents the method that was introduced and employed for the development and the successful certification of the software for the vehicle control unit (VCU) of the Vossloh Locomotives’ G6 shunting locomotives. The primary goal in the development of the software was conformity to EN50128, the secondary goal is a cost-efficient process without sacrificing safety. To achieve these goals our method is based on formal techniques, but also designed to be easily applicable in our context (pragmatics). Central to our method are functional trees as a design specification mechanism. The outcome of employing this method was the successful certification of the locomotive G6 without any software-related problems.