Earticle

In order to reduce or eliminate the consequences of the electronic equipment malfunction, some important electronic equipment were installed protection devices. Failures of protection devices are of hidden feature, and can only be found by inspections. Protection device failing to system malfunctioning has a delay characteristic. According to this delay characteristic, an inspection policy was proposed based on delay time model. An inspection model was developed to minimize the average cost per unit time with constraint of availability. Based on the model, optimal inspection interval can be determined to meet the objective of the opti