Rockmass parameters are used in the design of engineering structures built in rock and soil. One of the most important of these parameters is the deformation modulus of rockmass (Emass). Empirical formulas, to determine Emass, developed by different researchers are used. These formulas use the elastic modulus of the rock material (Ei)as a parameter. This value is a constant value in the design. However, engineering structures remain under different loads depending on many factors, such as topography, geometry of the structure, rock/soil properties. Time is other important parameter for rock/soil structure. In the new proposed method, the use of different Emass calculated from empirical formulas using the different Ei, which has different values under different loads as time dependent, was investigated in rock/soil structures during design. The performance of the stability analysis using different Emass was questioned by numerical modeling method. The integrated sub-routine contains the formula for the Emass, which is calculated from the Ei under time dependent and different constant loads in the laboratory. As a result of investigations conducted in 12 different field studies.