[en] This paper presents a comparison of dynamic responses of piping systems subject to independent-support excitation using the response spectrum and time-history methods. The BNL finite-element computer code PSAFE2 has been used to perform all the analyses. The time-history method combines both the inertia as well as static effect on the piping responses due to independent-support excitations at each time point, thus representing the actual responses. A sample problem is analyzed subjected to two independent support excitations and the results are presented in comparison with the response spectrum methods with uniform or independent-support motion