Can we know upfront how to prioritize quality requirements?

Quality requirements prioritization is a complex multi-criteria decision making process that stakeholders face in any phase of software development. Several surveys have been carried out to identify the most important quality requirements considered in various domains and stakeholder perspectives. There is a lack of understanding, however, about how the perceived importance of these qualities can change during development. We conducted an empirical study for analyzing the evolvability of quality requirements prioritization from software architect viewpoint at different phases of a services-oriented design process. We found that interoperability and reliability emerge as the most stable quality requirements for the project in smart transportation domain, whereas usability and security were the least stable in comparison with other qualities identified by 19 teams along the project. These results can be used at project start to include the most relevant quality requirements, and in particular to prioritize those that should be "always there" (if stable) or those that demand specific attention (if unstable).