4:2:1 Allocation of Test Units
One question that you should consider when planning a multiple stress accelerate life test (ALT) is the allocation of test units to the various stresses.
We want to create a model detailing the relationship between stress and time to failure. We also want to project the time to failure estimates to use conditions. Ideally, we test at nominal conditions only and gather time to failure information. We do not have the luxury of time thus explore using ALT.