16,874 research outputs found
Report on the Standardization Project ``Formal Methods in Conformance Testing''
This paper presents the latest developments in the âFormal Methods in Conformance
Testingâ (FMCT) project of ISO and ITUâT. The project has been initiated to study
the role of formal description techniques in the conformance testing process. The goal
is to develop a standard that defines the meaning of conformance in the context of formal
description techniques. We give an account of the current status of FMCT in the
standardization process as well as an overview of the technical status of the proposed
standard. Moreover, we indicate some of its strong and weak points, and we give some
directions for future work on FMCT
Requirements traceability in model-driven development: Applying model and transformation conformance
The variety of design artifacts (models) produced in a model-driven design process results in an intricate relationship between requirements and the various models. This paper proposes a methodological framework that simplifies management of this relationship, which helps in assessing the quality of models, realizations and transformation specifications. Our framework is a basis for understanding requirements traceability in model-driven development, as well as for the design of tools that support requirements traceability in model-driven development processes. We propose a notion of conformance between application models which reduces the effort needed for assessment activities. We discuss how this notion of conformance can be integrated with model transformations
Formal Methods in Conformance Testing: A Probabilistic Refinement
This paper refines the framework of âFormal Methods in Conformance Testingâ by introducing
probabilities for concepts which have a stochastic nature. Test execution is refined into test
runs, where each test run is considered as a stochastic process that returns a possible observa-
tion with a certain probability. This implies that not every possible observation that could be
made, will actually be made. The development process of an implementation from a specifica-
tion is also viewed as a stochastic process that may result in a specific implementation with a
certain probability. Together with a weight assignment on implementations this introduces a
valuation measure on implementations. The test run probabilities and the valuation measures
are integrated in generalized definitions of soundness and exhaustiveness, which can be used
to compare test suites with respect to their ability to accept correct, and to reject erroneous
implementations
Conformance Testing with Labelled Transition Systems: Implementation Relations and Test Generation
This paper studies testing based on labelled transition systems, presenting two test generation algorithms with their corresponding implementation relations. The first algorithm assumes that implementations communicate with their environment via symmetric, synchronous interactions. It is based on the theory of testing equivalence and preorder, as is most of the testing theory for labelled transition systems, and it is found in the literature in some slightly different variations. The second algorithm is based on the assumption that implementations communicate with their environment via inputs and outputs. Such implementations are formalized by restricting the class of labelled transition systems to those systems that can always accept input actions. For these implementations a testing theory is developed, analogous to the theory of testing equivalence and preorder. It consists of implementation relations formalizing the notion of conformance of these implementations with respect to labelled transition system specifications, test cases and test suites, test execution, the notion of passing a test suite, and the test generation algorithm, which is proved to produce sound test suites for one of the implementation relations
Testing real-time systems using TINA
The paper presents a technique for model-based black-box conformance testing of real-time systems using the Time Petri Net Analyzer TINA. Such test suites are derived from a prioritized time Petri net composed of two concurrent sub-nets specifying respectively the expected behaviour of the system under test and its environment.We describe how the toolbox TINA has been extended to support automatic generation of time-optimal test suites. The result is optimal in the sense that the set of test cases in the test suite have the shortest possible accumulated time to be executed. Input/output conformance serves as the notion of implementation correctness, essentially timed trace inclusion taking environment assumptions into account. Test cases selection is based either on using manually formulated test purposes or automatically from various coverage criteria specifying structural criteria of the model to be fulfilled by the test suite. We discuss how test purposes and coverage criterion are specified in the linear temporal logic SE-LTL, derive test sequences, and assign verdicts
Runtime Verification Based on Executable Models: On-the-Fly Matching of Timed Traces
Runtime verification is checking whether a system execution satisfies or
violates a given correctness property. A procedure that automatically, and
typically on the fly, verifies conformance of the system's behavior to the
specified property is called a monitor. Nowadays, a variety of formalisms are
used to express properties on observed behavior of computer systems, and a lot
of methods have been proposed to construct monitors. However, it is a frequent
situation when advanced formalisms and methods are not needed, because an
executable model of the system is available. The original purpose and structure
of the model are out of importance; rather what is required is that the system
and its model have similar sets of interfaces. In this case, monitoring is
carried out as follows. Two "black boxes", the system and its reference model,
are executed in parallel and stimulated with the same input sequences; the
monitor dynamically captures their output traces and tries to match them. The
main problem is that a model is usually more abstract than the real system,
both in terms of functionality and timing. Therefore, trace-to-trace matching
is not straightforward and allows the system to produce events in different
order or even miss some of them. The paper studies on-the-fly conformance
relations for timed systems (i.e., systems whose inputs and outputs are
distributed along the time axis). It also suggests a practice-oriented
methodology for creating and configuring monitors for timed systems based on
executable models. The methodology has been successfully applied to a number of
industrial projects of simulation-based hardware verification.Comment: In Proceedings MBT 2013, arXiv:1303.037
Testing timed systems modeled by stream X-machines
Stream X-machines have been used to specify real systems where complex data structures. They are a variety of extended finite state machine where a shared memory is used to represent communications between the components of systems. In this paper we introduce an extension of the Stream X-machines formalism in order to specify systems that present temporal requirements. We add time in two different ways. First, we consider that (output) actions take time to be performed. Second, our formalism allows to specify timeouts. Timeouts represent the time a system can wait for the environment to react without changing its internal state. Since timeous affect the set of available actions of the system, a relation focusing on the functional behavior of systems, that is, the actions that they can perform, must explicitly take into account the possible timeouts. In this paper we also propose a formal testing methodology allowing to systematically test a system with respect to a specification. Finally, we introduce a test derivation algorithm. Given a specification, the derived test suite is sound and complete, that is, a system under test successfully passes the test suite if and only if this system conforms to the specification
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Using formal methods to support testing
Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent
years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing
Geometrical Product Specification and Verification as toolbox to meet up-to-date technical requirements
The ISO standards for the Geometrical Product Specification and Verification (GPS) define an internationally uniform description
language, that allows expressing unambiguously and completely all requirements for the geometry of a product with the corresponding
requirements for the inspection process in technical drawings, taking into account current possibilities of measurement and testing
technology. The practice shows that the university curricula of the mechanical engineering faculties often include only limited classes on
the GPS, mostly as part of curriculum of subjects like Metrology or Fundamentals of Machine Design. This does not allow students to
gain enough knowledge on the subject. Currently there is no coherent EU-wide provision for vocational training (VET) in this area.
Consortium, members of which are the authors of this paper, is preparing a proposal of an EU project aiming to develop appropriate
course
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