Non-functional properties (NFPs) concern various characteristics of a system (cost, power, QoS). These characteristics belong to different models of the system, built by different design teams, using different formalisms. Therefore, the design of a system includes a number of domain-specific modeling languages, used to express various NFPs. This paper focuses on the heterogeneity of the points of view on the system. We show that "multi-view" approaches which do not rely on a unique underlying model appear better-suited to express NFPs than model weaving or annotations. However, existing approaches in this category do not yet support model execution. We introduce a multi-view extension to ModHel'X, a framework for executing heterogeneous models, and we show how it can be used for modeling non-functional characteristics of a system and expressing NFPs. A key point of this approach is that it relies only on the core concepts of ModHel'X, but uses them in new ways.