Winfried Dulz

Friedrich-Alexander-University of Erlangen-Nürnberg | FAU · Department of Computer Science

This paper examines techniques for the model-based testing of web applications and multilingual websites. For this purpose, the simple web game application GuessNumbers is used to explain the essential steps for a model-based test process that applies statistical usage models to generate appropriate test suites. We also discuss methods for performi...

This paper examines techniques for the model-based testing of web applications and multilingual websites. For this purpose, the simple web application HelloMBTWorld is used to explain the essential steps for a model-based test process that applies statistical usage models to generate and evaluate appropriate test suites. Model-based techniques that...

High-level formal modeling is a beneficial method for assisting system architects in early performance evaluations of desired hardware/software architectures and for coping with the continuously increasing complexity of heterogeneous systems. Modeling languages like UML allow expressive and concise specifications of algorithms, platforms, and infrast...

The development of complex software and embedded systems is usually composed of a series of design, implementation, and testing phases. Challenged by their continuously increasing complexity and high-performance requirements, model-driven development approaches are gaining in popularity. Modeling languages like UML (Unified Modeling Language) cope...

Test-driven Agile Simulation (TAS) is a general-purpose approach that combines model-driven engineering, simulation, and testing techniques to improve overall quality for the development process. TAS focuses on the construction of system and test specification models that are conform to the standards provided by the Object Management Group (OMG). S...

Image processing systems are characterized by very high computational demand caused by large amounts of data, short response times, and the complexity of image processing tasks. For these reasons, specialized hardware solutions based on multiple processing cores, complex interconnects, or custom hardware elements are used for image processing. Due...

A main goal of the Test-driven Agile Simulation (TAS) approach is to improve the overall quality of the development process of complex systems. The approach is premised on the combination of the standard model-based engineering, simulation, and testing techniques. It provides the transformation of specification models to executable simulation code...

The main purpose of this paper is to show how model-based techniques are used to efficiently control the generation of less complex test suites. By directed adjusting specific probability values in the usage profile of a Markov chain usage model it is relatively easy to generate abstract test suites for different user classes and test purposes in a...

An approach is presented in which both simulation and testing based on UML are combined in one framework to achieve an improved overall quality. System models are specified by UML diagrams, and are then mapped on C++-code and executed in the OMNeT++ network simulation framework. State-space oriented test models are defined independently from this t...

We will first give a brief introduction to a versatile modeling environment that allows the early validation of system specifications by a test-driven agile simulation approach. The main focus of our paper is on providing techniques for automated test case generation relying on statistical usage models. Based on the open source software R for stati...

Statistical usage testing of hardware/software systems is based in the main on a Markov chain usage model. This kind of model represents the expected use of the system by a usage profile, i.e. appropriate probability values that are attached to the state transitions. In this paper we present a constraint-based polyhedron approach to calculate the p...

The TestUS framework offers a range of techniques to obtain a TTCN-3 test suite starting from UML 2.0 requirement definitions. Use case diagrams that contain functional and non-functional requirements are first transformed to a Markov Chain usage model (MCUM). Probability annotations of MCUM state transitions enable the generation of TTCN-3 test ca...

The systematic generation of test cases from statistical usage models has been investigated recently for specific application domains, such as wireless communications or automotive applications. For Markov chain usage models, the expected usage of a hardware/software system is represented by transitions between usage states and a usage profile, mea...

The Extended Automation Method (EXAM) is employed by AUDI AG - one of the leading car manufacturers in Europe - to design and execute test cases for the purpose of component and system-testing. Test cases are specified using platform independent UML sequence diagrams. In order to provide an executable test suite platform dependent code is automatic...

We show the advantages of integrated tool support for eval-uating Vehicular Ad Hoc Network (VANET) scenarios. This includes three primary aspects. First, we provide support for convenient graphical modeling using UML diagrams and automated model transformation into executable simulation code using the Syntony framework. Secondly, a bidirectional co...

The TestUS framework (Statistical Testing based on use case scenarios) offers unique techniques and tools to obtain a TTCN-3 test suite starting from UML 2.0 requirement definitions. Use case diagrams that contain functional and non-functional requirements are transformed to a Markov Chain usage model (MCUM) in a completely automatic approach. The...

This paper describes a fully automated approach to statistically derive and run test cases. In this process scenario descriptions are used to construct an automata-based usage model as the test model responsible for the generation of test cases. Besides others, performance issues are considered and it is explained how to integrate these into the de...

The objective of this paper is to automatically generate a MCUM (Markov chain usage model) starting from an OMG UML-SD (sequence diagram) in order to derive TTCN-3 (testing and test control notation version 3) compatible test case definitions. Our approach is a combination of statistical usage testing and specification-based testing. Within this pa...

In this paper, we present a general framework for testing time-critical systems and software, as it is proposed in the European IST project MaTeLo. The main focus is on automatically generating a MCUM (Markov chain usage model) starting from an FDT (formal description technique) description in order to derive TTCN-3 (testing and test control notati...

In this paper a general framework is presented for testing time-critical systems and software. The main focus is to derive a state-oriented statistical usage model from a set of usage scenarios in order to automatically generate test cases. We describe a methodology that was developed within the European IST project MaTeLo to ease testing by combin...

We present a new approach for early performance prediction based on MSC specified systems in the context of SDL. Our approach is integrated into existing design methodologies as proposed by commercial tool vendors where communication software is fully specified in SDL and the final implementation is derived from there. Obviously the structure of th...

We present a new approach for early performance prediction based on MSC speciied systems in the context of SDL. Our approach i s i n tegrated into existing design methodologies as proposed by commercial tool vendors where communication software is fully speciied in SDL and the nal implementation is derived from there. Obviously the structure of the...

SDL and MSC are standardized specification techniques for the development of reactive real-time systems and protocol architectures. Whereas MSC scenarios only allow to specify the dynamic system behavior in form of event/time diagrams, SDL specifications are used to describe static and functional aspects of the system as well. In this paper a frame...

. Recent advances of physical communication media allow data transmissions at very high transmission capacity and low error rates. Concurrent to this evolution, an increase interest in real-time and multimedia applications can be seen in science, medicine, manufacturing, as well as entertainment. The design, planning and construction of these new c...

Protocol testing implies the functional analysis of a given implementation under test as well as its temporal performance evaluation. If protocols are formally specified sophisticated techniques and tools exist for analyzing functional properties, e.g. finding deadlocks or livelocks. Methods, however, for the temporal performance evaluation of form...

We present a model for distributed systems, where each node consists of two kinds of contextfree devices: grammars generate sequences of messages due to their context-free production set, which are send over the network; pushdown automata accept or reject incoming network messages with respect to their recognition rules. Assuming that the network i...

Profound results in the performance evaluation of communication systems can only be achieved if an abstract model of the system as well as the system's workload is given. Most techniques for workload characterization of communication systems either use stochastic descriptions based on characteristic performance parameters or represent the workload...

In this report, we give an overview how to use XML based techniques in order to derive language independent Markov Chain Usage Models (1) given any popular FDT (Formal Description Techniques), such as MSC (Message Sequence Charts, ITU-T standard Z.120) and UML/SD (Unified Modeling Language/Sequence Diagram, OMG Standard). In particular, we demonstr...

Zugl.: Erlangen, Nürnberg, Univ., Diss., 1989.

We describe model-level unit tests for model-driven simula-tion based on UML models. We refer to the well-known unit testing method and apply this concept on a higher abstrac-tion level, that is on UML simulation models. The concept of model-based simulation has become more and more popular throughout the last years. This trend is fostered by the a...