Jens R. Calamé

TTCN-3 Testing of Hoorn-Kersenboogerd Railway Interlocking

Railway control systems are safety-critical, so we have to ensure that they are designed and implemented correctly. Testing these systems is a key issue. Prior to system testing, the software of a railway control system is tested separately from the hardware. The interlocking is a layer of railway control systems that guarantees safety. It allows to execute commands given by a user only if they are safe; unsafe commands are rejected. Railway interlockings are central to efficient and safe traffic management for railway infrastructure managers and operators. European integration requires new standards for specification and testing interlockings. Here we propose an approach to testing interlockings with TTCN-3 and give an example for its application. The code of interlockings is simulated during test execution. For assessing the quality of the tests, we propose an approach inspired by the classification tree method

Data abstraction and constraint solving for conformance testing

Conformance testing is one of the most rigorous and well-developed testing techniques. Model-based test generation is an essential phase of the conformance testing approach. The main problem in this phase is the explosion of the number of test cases, often caused by large or infinite data domains for input and output data. In this paper we propose a test generation framework based on the use of data abstraction and constraint solving to suppress the number of test cases. The approach is evaluated on the CEPS (common electronic purse specifications) case study.

Automatic Model-Based Generation of Parameterized Test Cases Using Data Abstraction

Developing test suites is a costly and error-prone process. Model-based test generation tools facilitate this process by automatically generating test cases from system models. The applicability of these tools, however, depends on the size of the target systems. Here, we propose an approach to generate test cases by combining data abstraction, enumerative test generation and constraint-solving. Given the concrete specification of a possibly infinite system, data abstraction allows to derive an abstract system, which is finite and thus suitable for the automatic generation of abstract test cases with enumerative tools. To execute abstract test cases, we have to instantiate them with concrete data. For data selection we make use of constraint-solving techniques.

Distributed analysis with µCRL: a compendium of case studies

Models in process algebra with abstract data types can be analysed by state space generation and reduction tools. The µCRL toolset implements a suite of distributed verification tools for clusters of workstations. We illustrate their application to large case studies from a wide range of application areas, such as functional analysis, scheduling, security analysis, test case generation and game solving.

Applying Model-Based Testing to HTML Rendering Engines --- A Case Study

Conformance testing is a widely used approach to validate a system correct w.r.t. its specification. This approach is mainly used for behavior-oriented systems. BAiT (Behavior Adaptation in Testing) is a conformance testing approach for data-intensive reactive systems. In this paper, we validate the applicability of BAiT to systems, which are not behavior-oriented (reactive) but document-centered. In particular, we apply BAiT to the test of the HTML rendering engine Gecko, which is used by Mozilla Firefox. In order to do so, we formally specify a part of the CSS box model in the specification language μCRL and implement a wrapper for the Gecko renderer. Then, we automatically generate test cases and run tests with BAiT in a controlled experiment in order to demonstrate our approach on the relevant part of Gecko.