 The paper presents a methodology for determining the optimal number of zones, position of zone control units, and assignment of electric components in zonal electrical slash electronic architecture for electromobility and autonomous driving in the automotive industry. The design of power supply and wiring harness is essential, and K-means clustering and Dijkstra's algorithm are used to optimize cable routing. ZCUs are crucial for in-vehicle data and information transport, and their position and number affect the architecture and wiring harness development. Simulations show that a suitable zonal architecture reduces wiring harness length, weight, and brings functional benefits, but the number of zones must be chosen carefully to avoid functional limitations. This article was authored by Jonas Meyer and Hans Christian Ruse.