Unified Modeling Language (UML) is widely used for modeling IT systems but lacks formal rules to ensure consistency across diagrams. This often leads to inconsistencies when shared elements are interpreted differently. To address this, architects use consistency rules that derive elements in target diagrams from more abstract source diagrams. However, these rules are often written in natural language and applied at the element level, making them difficult to reuse or integrate with modeling tools. This paper introduces composite consistency rules-higher-level patterns that combine simple rules into more intuitive, reusable structures. These rules reflect architects design practices and support systematic, error-resistant model development. Implemented as JScript scripts in Sparx Enterprise Architect, they improve automation, reduce redundancy, and accelerate design. Composite rules enhance the consistency and completeness of UML architectures and can be reused across projects. They also support pattern-driven modeling and open possibilities for AI-assisted architecture generation and code integration.