In a method of customizing a software-implemented business process on a mobile computing device, subscriptions are defined to business solutions entities that are defined by metadata. An interface unit, situated at an arbitrary point in the ring line or integrated into one of the multimedia units establishes a radio connection between the multimedia system and an external unit, which for example transmits traffic information to the multimedia system. Furthermore, a valve assembly is to be provided which can be used equally for pipe disconnectors of the type CA and for pipe disconnectors of the type BA. The space inside the ring component allows the dough to rise during cooking without obstruction by the susceptor ring and without imparting thermal energy from the susceptor ring to the dough surface.