The lifetime performance index is commonly utilized to assess the lifetime performance of products. Based on the testing procedure for the lifetime of products following Chen distribution, an experimental design for progressive type I interval censoring is determined to achieve the desired power level while minimizing total experimental cost. For fixed inspection interval lengths and an unfixed number of inspection intervals, the required number of inspection intervals and sample sizes to achieve the minimum experimental costs are computed and presented in a table format. For unfixed termination times, the required number of inspection intervals, minimum sample sizes, and equal interval lengths are obtained and presented in a table format, while the minimum experimental costs are achieved. Finally, a practical example is presented to demonstrate the utilization of this experimental design for collecting samples and conducting a testing procedure to evaluate the lifetime performance of products.
