Research Activities
PhD Thesis
Abstract
The cost of software faults has increased from 59 billion USD in 2002 to 1.7 trillion USD in 2017. To alleviate this cost, the consensus among software engineers is to test as early and as often as possible. This, however, is not adopted by many software development teams. Most often, there are limited resources available for testing compared to the development of a product. Therefore, new techniques and methods are needed to improve testing quality in practice. Currently, most software companies rely on simple coverage metrics to assess the quality of their tests. Yet, the academic literature proposes the use of mutation testing to assess and improve the quality of software tests. Despite the promising results of mutation testing, it is not yet widely adopted in industry. We attribute this to three main problems: the performance overhead, lack of domain knowledge in tool providers, and lack of tool support. In this thesis, we address these three problems. Our results show that it is feasible to adapt the process of mutation testing based on industrial needs.
Links
Graduate Work
Master of Management Thesis, Vrije Universiteit Brussel (2025)
AllSimEx: Simulating Dynamic Aspects of Organ Allocation Ali Parsai. Promotor: Sam Verboven. Master of Science in Management, Vrije Universiteit Brussel (Faculty of Social Sciences & Solvay Business School), 2025.
Abstract
Management of organ transplantation is an important topic due to the scarcity of donated organs and the long wait lists across the world. Therefore, research into organ allocation policies is required in order to achieve an equitable outcome and increase the general life expectancy of the patients waiting for an organ. One of the problems facing this research is the lack of realistic simulators capable of assessing policies where degradation of the quality of the donated organ due to factors such as decision time are taken into account. In this study we present AllSimEx, and extended version of AllSim, a generic simulation platform for organ allocation. We implement DynamITE, a dynamic organ allocation policy, and compare the results of our experiment with those of DynamITE's original study to demonstrate the feasibility and reliability of creating a simulation platform capable of assessing such policies. Our results show that the experimental outcomes of AllSimEx are similar to those of DynamITE's original study.
Keywords: Organ Transplantation, Organ Allocation, Simulator
Links
Vrije Universiteit Brussel Library Page
Master's Degree, University of Antwerp
The article resulting from Research Internship 1 titled "Considering Polymorphism in Change-Based Test Suite Reduction" was accepted in RefTest2014. You can find the abstract below. The full preprint version can be found here. The final publication is available at link.springer.com.
With the increasing popularity of continuous integration, algorithms for selecting the minimal test-suite to cover a given set of changes are in order. This paper reports on how polymorphism can handle false negatives in a previous algorithm which uses method-level changes in the base-code to deduce which tests need to be rerun. We compare the approach with and without olymorphism on two distinct cases —PMD and CruiseControl— and discovered an interesting trade-off: incorporating polymorphism results in more relevant tests to be included in the test suite (hence improves accuracy), however comes at the cost of a larger test suite (hence increases the time to run the minimal test-suite).
The report for the Research Internship 2 titled "Literature Survey on Mutation Testing" can be found here. You can find the abstract below.
Mutation testing is one of the leading methods of testing the test-suites. In this article we review the literature about mutation testing in order to provide a guide for a developer who wants to design a mutation testing framework. We explore the diverse nature of mutation operators as a main ingridient to any mutation testing framework, and also discuss the features of the tools developed in the past decade.
The abstract for the Master's Thesis is provided below.
In order to assess the ability of a test suite to catch bugs, a quality metric is needed which can simulate realistic situations. Mutation analysis provides this metric with a reliable and repeatable approach. However, because of the computationally intensive nature of mutation analysis and the difficulties in applying such a technique to complex systems, it has not been widely adopted in industry. This study aims to determine the feasibility of using this technique on an industrial case, and to find out if the information gathered by this method is worth the performance costs.
You can download the tool developed for the thesis (LittleDarwin) here. The final thesis report is available here.
Research Interests
- Mutation Testing
- Software Quality Assessment
- Software Testing
- Digital Twins
- Cyber-Physical Systems