A System Dynamics Model for Inventory Decisions in Radionuclide Generators

A system dynamics model for simulating radionuclide generators inventory management decisions is presented in this research report. The radiopharmaceutical is generated gradually from another radioactive element, so called mother element in the radionuclide generators, and after each extraction of the produced radioactive material, so called elution, the radiopharmaceutical is produced in the proportion of the residue from the mother element. Based on the remained mother element, production time dependence,  mutual interaction of variables, nonlinear distribution function, and reproduction, lead to the incremental complexity of the mathematical model and cause the model making affair harder in common place operation research methods. In the proposed model appeared in this report, the above-mentioned factors are modeled and due to the nature of system dynamics models' development and the possibility of developing the boundary of the model, the feasibility of utilizing the model, as a basic one, in more complex modeling affairs is presented. The model behavior re-production tests and the system dynamics' extreme conditions, illustrate the validity of the proposed model. Ultimately, in this paper, several scenarios for the productivity raise are illustrated and twenty five percent improvement has been shown compared to the conventional models.