Proposed Objectives: This proposal aims at supporting the visits of Dr. Michail Papadakis to the Software Systems Engineering group (SSE) at the University College of London (UCL) with the overall aim of establishing a research collaboration between the SSE group at UCL and the SEcuRity design and VALidation (SERVAL) research group of the Interdisciplinary Centre for Security, Reliability and Trust (SnT) center of the Luxembourg University. The ultimate objective of the collaboration is threefold, a) to forge a tighter connection between the SSE and the SERVAL research groups both for joint funding applications and for the cross-fertilization of students and faculty in these two groups, b) to conduct world leading research and c) to expand the expertise of Dr. Papadakis through the day to day collaboration with the members of SSE group. Since both SERVAL and groups have a strong research record on software testing, search-based software engineering and software product line engineering, their collaboration can lead to significant research contributions. The targeted area of the research is the highly configurable systems. Proposed Research: Businesses, financial, health, communication, transportation and every other service of a modern society rely on software. Thus, a rising demand for its amplified reliability has been established. Additionally, IT sector companies are required to continuously adapt their products so that they can move on new markets and innovation potentials. This is a major challenge for IT, since products shall be adapted to these new targets. Hence, the overall cost and risk of the production of the adapted product variants can be very high. In view of this, IT industry tends to develop highly configurable systems as a possible way to re-use parts of the previously produced products. Yet, the current IT design practices are not industrialized enough to be able to effectively and efficiently test product variants. This results in an exceedingly expensive development cost or to a low overall quality and reliability of the software products. In TDHCS project we aim at proposing automatic techniques for the effective detection and diagnosis of software defects of highly configurable systems. Engineering highly configurable systems results in reducing both the maintenance effort and the time to market of software products and thus, they are increasingly adopted by industry. Configurable systems are software families consisting of similar systems with many variations. Such families are managed through configuration options of the developed systems and hence, tailored software products are constructed through the combination of the proposed options. Being able to efficiently test a product variant raises two important issues, a) the identification of variability with respect to other potential products and b) testing the program functionality that varies from the existing products. In view of this, the TDHCS project addresses two crucial dimensions: establishing dynamic analysis techniques dedicated to highly configurable systems for the effective testing and debugging of these systems. The challenging points of the project are: 1.The handling of the combinatorial explosion problem when testing.2.The application of computationally expensive testing techniques like mutation testing.3.The development of novel debugging techniques to reason about failures.Engineering issues of highly configurable systems form a relative new area of research motivated by the wide adaptation of these advances in industry. Therefore, the outcome of this work will be the submission of at least one paper to a top software engineering venue followed by an extended journal version. Additionally, in the longer term, this collaboration can be reinforced through joint projects, i.e. EU projects, that will fund, extend and exploit further the outcomes of this work.