The functions provided by the E/E system of modern vehicles can be assigned to the classical domains of powertrain, chassis, body and multimedia. Upcoming functions are forming new domains for advanced driver assistance and cloud integration. Therefore networking of functions is not limited to the vehicle but includes also the cloud. These trends imply major changes like the introduction of Ethernet as onboard networking technology or increasing safety and security needs.To design the best E/E architecture three groups of optimization targets are most relevant: Global vehicle targets, E/E targets derived from the implemented vehicle functions and product line targets for an E/E architecture.The PREEvision approach for E/E architecture design and optimization is a model based approach - inspired by the relevant and widely accepted automotive standards. Import and export filters allow the easy integration with PREEvision and complementation of existing tool chains. They also allow easy and fast introduction and data migration. The PREEvision data model is open and fully accessible by a scripting language. The data model follows the proven systems engineering principles of abstraction, decomposition and reuse. An integrated product line and variant management concept supports the design of E/E architecture platforms used for different vehicles.Optimization targets can be defined as customer specific metrics, which can be applied to dedicated vehicle variants.Architecture design is an ongoing process in parallel to series production development. This means architecture decisions are done not only at the beginning but also in parallel to series production development.