Calculation of Quantities of Spare Parts and the Estimation of Availability in the Repaired as Old Models

In this paper, based on the repair as old model under the same storage condition, the quantities of spare parts M for N identical systems is derived on the condition that failures are repaired with probability P0, a special example is given to prove the feasibility. Besides, availability function expression is provided at the same time, and taking system which follows Weibull distribution as the case, the validity of system is shown through calculation.