Abstarct: Abstract As surface mining operations expand and mining goes deeper, the amount of waste produced also increases. This increase leads to the enlargement of waste piles and poses a threat to the stability of these waste dumps. Due to limited space for waste disposal, environmental challenges, and other factors, Gole Gohar Mine 4 in Sirjan is unable to create new waste dumps. Given these existing constraints, the mine has explored the option of increasing capacity by adding benches. In this thesis, the stability of waste dumps has been assessed using the Limit Equilibrium Method with the Slide3D software. Additionally, probabilistic analysis has been conducted using the Monte Carlo method to assess potential risks and uncertainties. The waste dump model was designed in the Surpac software, and the volume of added benches was determined using this software. The acceptable safety factor in this assessment has been considered in the range of 1.15 to 1.2. In two consecutive benches, approximately 36 million cubic meters have been added, and the results indicate that the safety factor of the waste dump at the mine using the Spencer, Jambu, and Bishop methods is 1.26, 1.199, and 1.226, respectively. Mine 4 requires 983.58 million tons of tailings to produce 73 million tons of iron ore, in total, by emptying 428 million tons of tailings in the northeast and eastern accumulations, with the addition of the benches, approximately 555 million tons of tailings are left for disposal, And a proposed plan for Mine 4 waste dump with 8 steps and a total capacity of 284 million cubic meters has been designed, according to its stability analysis, the safety factor with three Spencer, Jambu and Bishop methods is 1.233, 1.124and 1.227 respectively. It is calculated. The proposed Eastern waste dump plan is not able to dispose of all the tailings of Mine 4, and for the remaining tailings, which is about 187 million cubic meters, space should be given to Mine 4 to dispose of the tailings.