This document describes a formalization, a solver-independant methodology and implementation alternatives for realizing constrained model search in a model-driven engineering framework. The proposed approach combines model-driven engineering tools ((meta)model transformations, models to text, text to models) and constraint programming techniques. Based on previous research, motivations to model search are first introduced together with objectives and background context. A theory of model search is then presented, and a methodology is proposed that details the different involved tasks. Concerning implementation, three constraint programming paradigms are envisionned and discussed. An open-source implementation based on the relationnal language Alloy is described and available for download.