In this paper, we discuss stochastic comparisons of lifetimes of parallel and series systems with independent heterogeneous Birnbaum–Saunders components with respect to the usual stochastic order based on vector majorization of parameters. Specifically, let X1,…,Xn be independent random variables with 620be5e9f4a043f" title="Click to view the MathML source">Xi∼BS(αi,βi),i=1,…,n, and be another set of independent random variables with . Then, we first show that when , 62d6805c3addbc49714"> implies and implies . We subsequently generalize these results to a wider range of the scale parameters. Next, we show that when , implies and . Finally, we establish similar results for the log Birnbaum–Saunders distribution.