The consideration of a growing number of design constraints is becoming a bottleneck in the design of analog and mixed-signal integrated circuits and is blocking more, much-needed automation in this area. In this paper, we propose a solution to these issues with a new methodology for constraint propagation and transformation. This technique allows designers and software tools to consider all relevant constraints when modifying a design, regardless of where these constraints were originally created. We integrated our ideas in an industrial design flow. The implementation of an electrical constraint type demonstrates the practical relevance. With constraints of this type the ON resistance of power stages in smart power ICs can be limited for the first time.