—This paper presents an operational semantics of the repetitive model of computation, which is the basis for the repetitive structure modeling (RSM) package defined in the standard UML Marte profile. It also deals with the semantics of an RSM extension for control-oriented design. The goal of this semantics is to serve as a formal support for i) reasoning about the behavioral properties of models specified in Marte with RSM, and ii) defining correct-by-construction model transformations for the production of executable code in a model-driven engineering framework. Keywords-Marte Repetitive Structure Modeling, dataparallelism, operational semantics, correctness