This paper reports essentials of a software product evaluation methodology, called CDSEM (Checklist Driven Software Evaluation Methodology), designed by Software Quality Laboratory of Tecnopolis CSATA Novus Ortus. Our intention is to focalize the use of software evaluation metrics in the framework of our methodology. We consider software product as composed by different parts: software system, product documentation, user documentation, support services and distribution media. Each component needs a specific set of metrics and tools for the evaluation process. After each component has been evaluated, the methodology provides an unified assessment process. The methodology proposes the evaluation models in accordance with the standard ISO 9126 (Information technology - Software product evaluation Quality characteristics and guidelines for their use) taking also into account the emerging new parts of the standard. The six characteristics defined in ISO 9126 (functionality, reliability, usability, maintainability, portability, efficiency), are exploded, for every component, into sublayers of abstractions till to the identification of the measurable items (metrics). Moreover, the methodology identifies, for each metric, tools and procedures for the evaluation (code measures, inspection etc.). A tool has been developed on PC platform (CDSET, Checklist Driven Software Evaluation Tool) to manage the methodology information base, results and reports.