This paper presents seven material discharge trajectory methods and explains the differences between them. Most of these methods involve a series of equations to determine first whether low-speed or high-speed conveying condition apply, then the material discharge angle for low-speed conditions and finally the X and Y coordinates of the trajectory profile. There are also simplified methods which rely on graphical determination of the trajectory profiles. The methods have been analysed to investigate which included parameters can be declared as variables for a given conveying condition and then evaluated to determine the impact of the variations. These parameters include, adhesive stress, coefficients of static and kinematic friction, air drag, particle shape and size, divergent coefficients and material bulk density.