Quality requirements (also known as non-functional requirements) are those that address the quality of the software. They involve diverse aspects such as availability, security, performance, scalability, portability and usability, among others. Continuous technological advances such as cloud computing or the Internet of Things present new challenges in guaranteeing a satisfactory level of quality in these aspects. Moreover, agile development methodologies, whose use is increasing, such as SCRUM, XP, Kanban, do not provide the necessary support for the management of these quality requirements. To support software engineers when making decisions about the level of quality needed in a project, it is essential to know in advance (1) what criteria will be considered to verify, prioritize, plan, and/or negotiate quality requirements. Likewise, it is necessary to specify (2) how these criteria will be evaluated and (3) what factors in the project context may affect that evaluation. To try to answer these 3 research questions, the authors of this article have designed and are carrying out a systematic literature review. This article presents for discussion the description of the methodology followed in that literature review, as well as some of the preliminary results obtained during its execution.