System dynamics in calculation on probability of spares sufficiency

To implement 'Focus Logistics', from the organizational-level maintenance view, the properties of dynamics in supplying flow of spares parts during the logistics support procedure were explored. The influence on the equilibrium between supply and demand was considered, and those influencing factors were involved in the procedure of spare parts logistics support. System Dynamics (SD) theory was applied to build a model which could simulate and measure the gap between supply and demand of spare parts varied with time, for organizational-level maintenance. Based on the simulation results, Probability of Spares Sufficiency was calculated, predicting the satisfaction degree of spare parts for a military unit in the future. The method could also aid to expound the mechanism of equilibrium between supply and demand, and forecast and evaluate the effectiveness of logistics system.