We propose a systems analysis framework based on goal modelling and transactions for improved decision-making about security solution architectures– with a specific focus on layered security of physical spaces and assets. The framework assists in defining more complete security strategies as well as analyzing tradeoffs between security and other factors such as cost and privacy. Using the conceptual transaction or Requirements-Execution-Delivery (or RED) Transaction model as the basis, we provide a dynamic virtual structure and methodology for security analysis. The benefit is that the implemented security can be optimized based onthe value to the various stakeholders and to minimize the benefit to the attacker.