By utilization of methods of radiation processing and radiation technology in the pilot and industrial scale the irradiation facility including the shieldings is the factor, which influences the costs mostly. Description and evaluation of partial systems by means of dose rate distributions is one of the important fundamentals for an optimal design. The complex relations require the application of computer methods. The combined application of computer experiments and dosimetry within the bounds of evaluation of existing facilities is the basis for working out an adequate computing model. The use of the model opens some new possibilities for the design of gamma-irradiation facilities. Possibilities and advantages of this practice are demonstrated by means of some examples of utilization of the code D0SKMF2 for problems of the ZfI.