Teaching

In this thesis different of algorithms covered in the course software maintenance should be visualized (for example the Hitting Set Algorithm by Reiter, Slicing with the PDG,...). As part of the work, suitable concepts to visually represent the algorithms have to be developed and subsequently, those visualizations should be implemented.

Different tools are to be identified and compared, which allow to analyze procedural or object priented programs (e.g. the Slicing Plug Kaveri. As part of the work different tools should be identified and compared in relation certain objectives such as capabilities, scope, performance etc.

Delta Debugging is a divide-and-conquer strategy that returns a 1-minimal erroneous input. QuickXplain is an algorithm that should find minimal explanations for over-constrained problems and is also based on a divide-and-conquer strategy. These two approaches should be compared on the one hand theoretically and on the other hand practically with each other. The goal is to define a unified framework to compare these different methods and examine whether the algorithms return the same result for the same input or how the results differ.

There are various slicing techniques beyond the usual suspects of static and dynamic slicing. For instance, quasi-slicing tries to balance between the two extremes that are static and dynamic slicing by only considering a portion of the input variables. Also extension to dynamic slicing such as simultaneous slicing exist, that explore several dynamic slices in conjunction. In this thesis, those and other approaches should be compared in regard to their capabilities to determine root causes for abnormal behavior in programs.

In this thesis the required worksteps for integrating a hardware to a cotinous integration (CI) (Hardware-in-the-loop) are explained by means of a an evaluation board. These worksteps are: communication between the board and the CI, execution of hardware relevant tests and control of the power supply for the hardware. This Hardware-in-the-loop setup should ensure a defined and stable behaviour of the hardware in a defined environment.

As software projects grow their test suites also increase in size as well as the time to execute the test suite. Test Suite Reduction (TSR) deals with identifying and removing redundant test cases from a test suite. The reduced test suite ideally fulfills the same requirements as the initial test suite and retains the fault detection capability of the original test suite.

While commonly used metrics such as line or method coverage have been applied extensively in theory and practice, we investigate a different type of coverage metric: checked coverage. The idea is that not only executed portions of the code are relevant but also if these parts of the code were checked by some type of test oracle. This thesis investigates whether checked coverage is suitable for TSR.

Model-based diagnosis derives explanations for discrepancies between the expected and observed system behavior by relying on a formal representation of the artifact under consideration. Although its theoretical background has been established decades ago and various research prototypes have been implemented, industrial applications are sparse. The thesis emphasizes the role of essential technology acceptance factors, i.e., usefulness and usability, within the context of model-based diagnosis. In particular, we develop a concept and interface design for an abductive model-based diagnosis application integrated into existing condition monitoring software for industrial wind turbines. This fault identification tool should enhance the performance of the maintenance personnel while respecting their current work processes, taking into account their particular needs, and being easy to use under the given work conditions. By employing an iterative design process, continuous feedback in regard to the users’ work goals, tasks, and patterns can be included, while also considering other stakeholders’ requirements. The result is a workflow and interface design proposal to be implemented in the final software product.