Application designers need to start the application design process before the final platform is available. Therefore, the designers need to have an abstract model of the platform at the early stages of the design process in order to validate the application functionality and evaluate its performance. Furthermore, platform designers need an application model to evaluate whether the computation and communication capacity of the platform is sufficient for the application. This paper identifies a minimalistic set of modelling constructs that can extensively characterise an application, which can be validated over a multicore Network-on-Chip (NoC) platform. The identified set of constructs is organized as a Unified Modeling Language (UML) profile in order to facilitate its use within UML-based design flows and tools. We present a practical application using the profile's constructs to model and constrain several subsystems of an autonomous vehicle control. Using the profile, we can cover sufficient aspects of the computation and communication requirements of the application, so that we can perform an extensive comparative analysis of alternative platform configurations very early in the design flow.