IEC/PAS 63131:2017(E) defines a set of operational control functions (objects) and the associated logical diagram (System Control Diagram (SCD)), for use in the continuous control process industry – e.g. as used in Oil and Gas processes.The main drivers for establishing this as a standard are the advantage of efficient engineering, implementation, and commissioning, as well as reuse of the control application across different suppliers of control systems. The diagrams give a logical representation that is suited for data transfer.This PAS also includes a method of documenting sequences and their interaction with the control objects.