Planning step-stress life-test with a target acceleration-factor

A sequential approach is presented to plan a multiple-steps step-stress acc elerated life test (SSALT) with type-I censoring so as to achieve a pre-spe cified acceleration factor. An initial optimal plan for a simple SSALT, whe re one not only has to determine the optimum hold-time under low stress but also the optimum low stress level, is obtained by solving a constrained no n-linear program. A backward recursion scheme generates the subsequent opti mal low-stress levels and hold-times for multiple-step SSALT. An illustrati on using a 3-step SSALT is presented. The relative efficiency of the 2-step and 3-step SSALT is investigated. A numerical example illustrates the meth od under 2-step and 3-step SSALT.