Research on the Cost of Two-dimensional Product Warranty Based on Imperfect Repair

The proportional hazard rate reduction factor and the time region under imperfect repair were variables.The cost of two-dimensional product warranty based on imperfect repair was modeled.The optimal proportional hazard rate reduction factor was determined firstly,and then the time region of imperfect repair was optimized with the two-stage process to minimize the expected warranty cost.Moreover,an illustrative numerical example is provided to the model.It shows that as the usage rate increase,the expected warranty cost for imperfect repair strategy is lower than that of minimal repair strategy.