As part of its research program to evaluate efficient design criteria for improved blast fragmentation, the U.S. Bureau of Mines has developed two computer programs to facilitate data analysis. Results of these two programs are used to better understand the fundamental parameters of blasting for surface mine rock fragmentation. The first program calculates the probability that an overlap or crowding will occur in the firing times of millisecond- delayed initiators. A statistical model is used to take into account initiator scatter to determine the probability of success (no overlaps and no crowding) for any size shot, including multihole and multidecked production shots. Monte carlo methods are used to randomize the firing times of the initiators. Results show that the probability of success is often greatly reduced even with very accurate initiators. The second program predicts, using multiple- variable regression analysis, the average fragment size from the shot design parameters. The results of the program can be used to study the effect of changes in burden, spacing, and explosive diameter on fragmentation. Additional variables, such as bench height, powder column length, subdrill, or stemming length, can also be included in the analysis. Variables such as rock type and fracture spacing can be included if they are quantified. The program was used to predict the average fragment size for 25 reduced- scale tests conducted at the University of Missouri at Rolla.