Flexibilities in Energy Systems are required to integrate renewable energy sources such as Photovoltaic and Wind Power. Cellular Energy Systems are discussed as a method to integrate and manage flexibilities such as Electrical Vehicles, Batteries and Controllable Loads on different levels of the Energy System. However, it is lacking a holistic flexibility model when extending the approach to Multi-Energy Systems (Electrical and Thermal Storages, Heat Pumps, CHPs, Fuel Cells, Electrolyzers etc.). This paper presents a flexibility model based on Affine Arithmetic which specifies allowed power and energy ranges while considering relations between time steps and energy forms.