This document contains the results obtained after the formalization process applied to the "Model of Process of the Usability and Accessibility Engineering (MPIu+a)" with SPEM language and its implementation with the Eclipse Process Framework Composer tool (EPFC). MPIu+a proposes the inclusion of usability evaluation transversely during the development of interactive systems, unlike many development processes normally used in the software industry. SPEM and EPFC application for this model arises from the need to classify MPIu+a as a purely engineering process.