Offshore Oil Platform Safety System

flowchart TB
  n0["system<br>Offshore Oil Platform Safety System"]
  n1["actor<br>Platform Operators"]
  n2["actor<br>Process Control System (DCS)"]
  n3["actor<br>Shore Emergency Coordination Centre"]
  n4["actor<br>Regulatory Authority"]
  n5["actor<br>Wellhead / Process Equipment"]
  n0 -->|Alarms, PA/GA, Evacuation Status| n1
  n1 -->|Manual Override, Acknowledgement| n0
  n2 -->|Process Data, Trip Setpoints| n0
  n0 -->|Shutdown Commands, Valve States| n2
  n0 -->|Emergency Notifications, Status Reports| n3
  n4 -->|Safety Regulations, Audit Requirements| n0
  n5 -->|Process Variables, Well Status| n0
  n0 -->|ESD Commands, BOP Activation| n5