The simulator < Shock Wave Stress and Displacement > depends on equations which are based on the fundamental laws of Physics, of Chemistry, and of Rock Mechanics.  It simulates the mechanisms which occur during a blast from the time of initiation till the burst out of the rock mass; in particular, it simulates the velocity U of the horizontal displacement of the rock at the free face of the bench.  The Optimum Delay, or DSB Delay (Dupont Sequential Blasting Delay), is based on the experimental criterion according to which the best fragmentation occurs if the rock at the face moves a distance of 1/3 the length of the burden B before initiation of the next row.  Thus a knowledge of U and B allows the Optimum Delay to be calculated; each simulation with the simulator < Shock Wave Stress and Displacement > tells the user the value of the Optimum Delay.