Non-parametric inference based on reliability life-test of non-identical coherent systems with application to warranty time

In this paper, we develop non-parametric statistical inferential methods for component lifetime as well as system lifetime distributions based on a life-test of non-identical coherent systems with known signatures. This is done through maximum likelihood estimation method based on EM-algorithm and the cumulative hazard approach of Nelson–Aalen estimation method. We then extend the method to a multiple-stress problem by assuming the components …