steadfastly by me through all bad times, and who always had unwavering faith in me, even when I sometimes lost that faith in myself. Today’s complex cyber-physical systems (CPSs) are created using models throughout the system development life cycle, a process referred to as model-based design (MBD). The heterogeneity of elements in CPSs requires multiple perspectives and formalisms to explore the complete design space. Ensuring the consistency of these various system models is an important part of the integrated MBD approach. In this thesis, we propose to unify heterogeneous system models through light-weight representations of their structure and semantics using architectural descriptions. Architectures are annotated structural representations that describe systems at a high level of abstraction, allowing designers to determine appropriate assignment of functionality to elements, and make trade-offs between different quality attributes. There are two fundamental shortcomings of current architecture modeling capabilities that limit their potential to fully address the engineering problems of large-scale, heterogeneous CPSs: (i) limited

Abstract. Software architecture is the result of a design effort aimed at ensuring a certain set of quality attributes. As we show, quality require-ments are commonly specified in practice but are rarely validated using automated techniques. In this paper we analyze and classify commonly specified quality requirements after interviewing professionals and run-ning a survey. We report on tools used to validate those requirements and comment on the obstacles encountered by practitioners when performing such activity (e.g., insufficient tool-support; poor understanding of user’s needs). Finally we discuss opportunities for increasing the adoption of automated tools based on the information we collected during our study (e.g., using a business-readable notation for expressing quality require-ments; increasing awareness by monitoring non-functional aspects of a system).