Janbu method assumes non-zero forces between blocks. Method satisfies the force equations of equilibrium in the horizontal and vertical directions for all blocks and the moment equation of equilibrium for all but the last (uppermost) slice. The assumption of this method is the choice of position of forces acting between the blocks. The factor of safety SF is found through the iteration of forces acting between blocks and then inclinations of these forces are calculated. Further details can be found in the section describing the analysis of a polygonal slip surface.