This work presents current methods to analyze and improve the architecture of Simulink models. The methods follow the “principles for architectural design” of part 6 on software development of the ISO 26262 functional safety standard for road vehicles, the dominating standard in the automotive industry. The methods presented describe how the abstract architectural principles of the ISO 26262 can be implemented in the context of model-based development using Simulink. Therefore we demonstrate how different metrics can be used to improve or enforce the compliance with the principles. In contrast to previous publications we will not primarily focus on the metrics itself, but emphasize the architectural principles themselves and expose the architectural implications of applying the metrics. As the architectural principles of the ISO 26262 are targeted at reducing the overall complexity, we will also focus on metrics and methods that help to reduce the models complexity.