Martin Kardos

Model-based Runtime Verification Framework for Self-optimizing Systems

This paper describes a novel on-line model checking approach offered as service of a real-time operating system (RTOS). The verification system is intended especially for self-optimizing component-based real-time systems where self-optimization is performed by dynamically exchanging components. The verification is performed at the level of (RT-UML) models. The properties to be checked are expressed by RT-OCL terms where the underlying temporal logic is restricted to either time-annotated ACTL or LTL formulae. The on-line model checking runs interleaved with the execution of the component to be checked in a pipelined manner. The technique applied is based on on-the-fly model checking. More specifically for ACTL formulae this means on-the-fly solution of the NHORNSAT problem while in the case of LTL the emptiness checking method is applied.

Model Based Formal Verification of Distributed Production Control Systems

The design of software for distributed production control systems (DPCS) is an error prone task. Ensuring the correctness of the design at the earliest stage possible is a major challenge in any software development process. In this context, formal verification is a very appealing approach in addition to simulation and testing, since it implies an exhaustive exploration of all possible behaviours of a system. In this paper, we present an approach towards model based formal verification for DPCS by means of model checking. The presented work is a part of the ISILEIT project that aims at the development of a seamless methodology for the integrated design, analysis and validation of distributed production control systems.

Comprehensive verification framework for dependability of self-optimizing systems

By integrating formal specification and formal verification into the design phase of a system development process, the correctness of the system can be ensured to a great extent. However, it is not sufficient for a self-optimizing system that needs to exchange its components safely and consistently over time. Therefore, this paper presents a comprehensive verification framework to guarantee the dependability of such a self-optimizing system at the design phase (off-line verification) as well as at the runtime phase (on-line verification). The proposed verification framework adopts AsmL as intermediate representation for the system specification and on-the-fly model checking technique for alleviating the state space explosion problem. The off and the on -line verifications are performed at (RT-UML) model level. The properties to be checked are expressed by RT-OCL where the underlying temporal logic is restricted to time-annotated ACTL/LTL formulae. In particular, the on-line verification is achieved by running the on-the-fly model checking interleaved with the execution of the checked system in a pipelined manner.

Towards Design Verification and Validation at Multiple Levels of Abstraction

The specification of software for distributed production control systems is an error prone task. The ISILEIT project aims at the development of a seamless methodology for the integrated design, analysis and validation of such embedded systems. Suitable subsets of UML and SDL for the design of such systems are therefore identified in a first step. The paper then focuses on how we use a series of formal semantics of our design language to enable the effective evaluation of software designs by means of validation and verification. We will further explain how the use of multiple Abstract State Machine meta-models permits simulation and model checking at different levels of abstraction

Increasing dependability by means of model-based acceptance test inside RTOS

Component-based self-optimizing systems can adjust themselves over time to dynamic environments by means of exchanging components. In case that such systems are safety-critical, the dependability issue becomes paramountly significant. This paper presents a novel model-based runtime verification to increase dependability for the self-optimizing systems of this kind. The proposed verification approach plays a role of an alternative acceptance test transparently integrated in RTOS, named model-based acceptance test. The verification is performed at the level of (RT-UML) models representing the systems under consideration. The properties to be checked are expressed by RT-OCL where the underlying temporal logic is restricted to either time-annotated ACTL or LTL formulae. The applied technique is based on the on-the-fly model checking, which runs interleaved with the execution of the checked system in a pipelined manner. More specifically, for ACTL formulae this means an on-the-fly solution to the NHORNSAT problem, while in the case of LTL formulae, the emptiness checking method is applied.

FUNCTIONAL VERIFICATION FOR UML - BASED MODEL DRIVEN DESIGN OF EMBEDDED SYSTEMS

Modeling and formal specification in combination with formal verification can substantially contribute to the correctness and quality of design of embedded systems and consequently help reduce the development costs. This paper tackles the problem of providing a fully automated formal verification for UML-based design of embedded systems. For verification it employs the model checking technique. Unlike other approaches, the paper focuses on supporting a consistent subset of UML diagrams that cover all main aspects of an embedded system, i.e. the structure, communication and behavior. The whole approach is evaluated on a case study of a Manufacturing Flow System with distributed control.

Verification Framework for UML-Based Design of Embedded Systems

System level design incorporating system modeling and formal specification in combination with formal verification can substantially contribute to the correctness and quality of the embedded systems and consequently help reduce the development costs. Ensuring the correctness of the designed system is, of course, a crucial design criterion especially when complex distributed (realtime) embedded systems are considered. Therefore, this paper aims at presenting a verification framework designated for formal verification and validation of UML-based design of embedded systems. It first introduces an approach of using the AsmL language for acquiring formal models of the UML semantics and consequently presents an on-the-fly model checking technique designed to run the formal verification directly over those semantic models.

ASMs as integration platform towards verification and validation of distributed production control systems at multiple levels of abstraction

Production systems used nowadays in manufacturing processes can be characterized as stationary, inflexible, production-specific systems with a strongly centralized control. Once such a production system has been built, it is very time and cost demanding to adapt it to new changes in the manufacturing process. On the contrary, the market competition and customer needs impose new requirements on the production systems. There are increasing demands for shorter production times, higher flexibility, reconfigurability and optimal utilization of production facilities. Such demands can be met only by distributed production systems (DPS) with a decentralized organization.