Optimal Planning of Reliability Life Tests Considering Prior Knowledge

An empirical-statistical demonstration of the lifetime of engineering products is necessary in order to assure fatigue and reliability requirements [1]. Engineers are faced with the challenge of selecting the most suitable test strategy and also the optimal parameter setting, e.g. sample size, in order to realize reliability demonstration with limited costs, time and with their available testing resources. In this paper, different test strategies such as Sudden Death, time-censored, failure-censored and non-censored tests, and the Success Run Test are compared in a Reliability DOE concerning the necessary time, costs and the Probability of Success of the whole test configuration. The DOE is carried out with standardized cost and time data and the results can therefore be used generally and are transferable to any other product. With the resulting data, the different test strategies are comparable in terms of different boundary conditions. The Probability of Success can be determined and compared for the different strategies with a very low computing time in terms of cost and time. Using these results, engineers are now able to select the most suitable test procedure for their individual reliability requirements. Finally, the applicability is presented in a case study, showing the difference between different test strategies for the demonstration of a specific reliability target.