This Technical Report describes the risk assessment methodology followed to determine the Performance Level required (PLr), as defined in EN ISO 13849-1:2008, for specific safety related parts of control system (SRP/CS) of rough-terrain variable-reach trucks covered by prEN 1459-1, EN 1459-2 and EN 1459-3. This Technical Report does not apply to SRP/CS that includes no electrical/electronic components. NOTE It is the intention of CEN TC150 WG2 to use the same methodology to develop future standards (e.g. further parts of EN 1459).