The invention relates to a method (19) of operating a hydraulic arrangement (1) including a mounting base (5), a boom (3) that is pivotably arranged on the mounting base (5), and a Z-kinematics (2) that is arranged on the boom (3). The Z-kinematics (2) tilts a tool attachment device (10), that is pivotably arranged on the boom (3). The boom (3) is moved by a lifting hydraulic piston (7) that is connected to the boom (3) and to the mounting base (5). The Z-kinematics (2) is moved by at least a tilting hydraulic piston (11) that is connected to a lever of the Z-kinematics (2) and to the mounting base (5). On application of an input control command for changing the position of the lifting hydraulic piston (7), a compensation command is automatically generated and applied to the tilting hydraulic piston (11), to essentially maintain the attitude of the tool attachment device (10). The compensation command is generated based on the input control command for the lifting hydraulic piston (7), using a mathematical model of the hydraulic arrangement (1).