Where does the human being fit in the normal operating system and where does he/she fit in the safety shutdown system? Planning ahead can make human interaction inherently, safer. Tb is paper offers tbe following suggestions for managing that interaction: 1) Use inherently, safer principles in the design of the process and its layers of protection. 2) Define "Never Exceed" limits for critical safe operating parameters, 3) Define a mandatory action point and a "Never Deviate" action with enough response time to prevent exceeding the Never Exceed limit. 4) Train and drill.