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In this paper we present a hierarchical method that decomposes a discrete-event system (DES) into a high level subsystem which communicates with ¢ ¡ ¤ £ parallel low level subsystems through separate interfaces, which restrict the interaction of the subsystems. We first review the setting for the serial case (¦ ¥ § £) [1], and then generalize it for¨¡ © £.(More)
—In this paper, we present a hierarchical method that decomposes a system into two subsystems, and restricts the interaction of the subsystems by means of an interface. We present definitions for two types of interfaces [represented as discrete-event systems (DESs)], and define a set of interface consistency properties that can be used to verify if a DES is(More)
—Flexible manufacturing systems have long been touted as an application area for supervisory control theory. Unfortunately, due to the typical exponential growth of state space with the number of interacting subsystems, concurrent systems such as manufacturing applications have, for the most part, remained beyond the reach of existing supervisory control(More)
Safety cases have become popular, even mandated, in a number of jurisdictions that develop products that have to be safe. Prior to their use in software certification, safety cases were already in use in domains like aviation, military applications, and the nuclear industry. Argument based methodologies/approaches have recently become the cornerstone for(More)
This paper describes the lessons we learned over a thirteen year period while helping to develop the shutdown systems for the nuclear generating station at Darlington, Ontario, Canada. We begin with a brief description of the project and then show how we modified processes and notations developed in the academic community so that they are acceptable for use(More)
—This paper considers supervisory control of probabilistic discrete event systems (PDESs). PDESs are modeled as generators of proba-bilistic languages. The supervisory control problem considered is to find, if possible, a supervisor under whose control the behavior of a plant is identical to a given probabilistic specification. The probabilistic supervisors(More)
Model comprehension and effective use and reuse of complex subsystems are problems currently encountered in the automotive industry. To address these problems we present a technique for extracting, presenting and making use of signatures for Simulink subsystems. The signature of a subsystem is defined to be a generalization of its interface, including the(More)