ISO 13849-2:2003

ISO 13849-2:2003 specifies the procedures and conditions to be followed for the validation by analysis and testing of:
the safety functions provided andthe category achieved
for the safety-related parts of the control system in compliance with EN 954-1 (ISO 13849-1), using the design rationale provided by the designer.
This International Standard does not give complete validation requirements for programmable electronic systems and therefore can require the use of other standards.