The selection of Free/Libre Open Source Software (FLOSS) tools for Analysis and Design (A&D) is a hard task due to their complexity, their wide variety within the market, and their functionality level. This article aims at introducing a group of quality features to evaluate FLOSS tools for A&D. Such features are presented based on the perspective of the Software Quality Systemic Model (MOSCA), inspired by ISO/IEC 9126 [9], Dromey 's quality model [5] and the Goal-Question-Metrics (GQM) Paradigm. This model includes attributes such as functionality, usability and maintainability, and establishes 52 new metrics for a total of 102 metrics that allow evaluating FLOSS tools for A&D within a specific context. Lastly, validation of this proposal is verified through its application on eight FLOSS-based A&D tools. © 2008 IEEE.