I. Introduction
Software-based digital solutions have become ubiquitous in our society, hence creating a need for developing software systems that meet the quality requirements of the relevant stakeholders. With the growing nature of such digital ecosystems, the need to include sustainability as a software quality has become imperative. Penzenstadler et al. [13] define software sustainability as "preserving the function of a system over a defined time span". Lago et al. [10] further describe sustainability as a property of software quality under four dimensions (4D): Economic (Ec), Environmental (E), Social (S) and Technical (T). To fulfill the sustainability quality requirements, the quality of software needs to be assessed (over a period of time) across 4D sustainability dimensions.