A cantilever structure subjected with two external forces along the X and Y direction. The mean and coefficient of variance (COV) for the force applied along the X axis is 3KN and 5% respectively. Similarly, the mean and coefficient of variance (COV) for the force applied along the Y axis is 5.4KN and 10% respectively. Both external forces are follow lognormal distribution. In order to consider the structure is failed, the tip displacement must be greater than to the allowable displacement. The mean and standard deviation of the allowable displacement is 76 and 3.8mm respectively