International audienceIn MDE, design of systems can be improved and accelerated thanks to reusable models which are made available in model repositories or libraries. This paper focuses on the construction and exploitation of “off-the-shelf” model template bases. Model templates are parameterized models which are adaptable to various application contexts. Due to their parameterization, model templates have their own modeling space. In this paper, we present the main modeling ac- tivities that underlie this space, their dedicated engineering processes and their actors, and we contribute to the model reuse improvement by detailing new tem- plate operators for the described modeling activities. A software environment is shown to illustrate template based engineering in Eclipse