A revisit of the proportional sampling strategy

When test cases are selected with replacement, we have P_pss ⩾P_r, where P_pss and P_r are the probabilities of detecting at least one failure by the proportional sampling strategy and random testing respectively. However, recent results on the proportional sampling strategy have highlighted that P _pss⩾P_r may be very sensitive to whether test cases are selected with or without replacement. The paper provides more insights into this important issue, as the proportional sampling strategy is the most practically applicable partition testing strategy and it always performs better than random testing