A new system design methodology is proposed that separates communicationfrom behavior. To demonstrate the methodology weapplied it to a simple ATM design. Since verification is clearly amajor stumbling block for large system design, we focussed on theverification aspects of our methodology.In particular, a simulator was developed that is based on the communicationparadigm typical of our methodology. The simulatorgives substantial performance improvements without sacrificinguser access to detail.Finally, the potential for this methodology to improve verification,modeling and synthesis is explored.