Factor of Safety (FoS), also known as safety factor, represent the load capacity of a structure/system relative to an intended load and It is simply defined as the ratio of strength over stress. A FoS of 1 means that a structure will collapse exactly when it reaches the design load, and no more additional load can be applied. Any mine design such as highwalls, slopes, pillar and etc, with FoS of less than 1 is not stable. FoS of 2 means that the designed structure will fail at twice the design load, and so on. In geotechnical engineering, FoS is expressed by the ratio of shear resistance to driving force along a potential failure plane.