This work is a proposal for the identification Non Functional Usability Requirements Specification, at an early stage. The procedure starts in a business processes modeling domain, where essential specifications are captured. Then they are mapped to a structure called Baseline Requirements using the concept of paradigm transformation from Model Driven Software Design. In this context, usability specifications are introduced inside the scenarios using transformations, and take part in these scenarios by using Lexicon Extended Language (LEL). The use of LEL allows to describe the usability specifications and the construction of a dictionary, which will later be needed for integrating the usability specifications in the software programs developed. This also provides the possibility to identify, define and maintain the traceability of usability specifications defined at early stages.Fil: Groppo, Mario Alberto. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación, Desarrollo y Transferencia de Sistemas de Información; Argentina.Fil: Moreno, Juan Carlos. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación, Desarrollo y Transferencia de Sistemas de Información; Argentina.Fil: Marciszack, Marcelo Martín. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación, Desarrollo y Transferencia de Sistemas de Información; Argentina.