An early evaluation of a product along with the consideration of life phase specific actor(s) and environment(s) can help greatly to gain an understanding of the product's behaviour and interactions. Virtual Reality (VR) can help designers to examine later life situations of a product by means of use case scenarios. However, preparing a VR-scene is still a time-consuming and cumbersome task. A model based approach that uses behaviour models of SysML to describe a VR-scene can reduce the preparation efforts. Such an approach is helpful if it allows the reuse of already described VR-scenes or their contents. This paper talks about the reusability of SysML behaviour models that constitute a VR-scene. This reusability can only be achieved by the generic definition of model interfaces. Therefore, a new modelling approach is presented to facilitate the reuse of SysML behaviour models to form different use cases of a product in VR. This approach also talks about the interface definitions and the management of variants of SysML models. The presented approach is elaborated by an example model that contains variants and uses instances to build different use cases.