Learning is changing in deep, activities of teaching practitioners have to evolve. They need to structure and formalize their internal designs as models to be implemented but do not have competences in instructional design. We propose to use patterns, semi-structured description of an expert's method for solving a recurrent problem to elicit and express theirs needs. We propose an engineering design process framework based on patterns, and pedagogical design schemes to support instructional design. A tool has been developed to support this process. We experiment a design session with two trainers of an association dedicated to back-to-work programs within an iterative co-participant design based research method.