IS 1893(Part-1)-2016 specifically mentions in the Clause 7.7.3 that base shear computed (Vb) from a dynamic analysis like a Response Spectrum analysis must be compared with the base shear obtained from using fundamental time-period Ta (i.e, by using Equivalent Static method. One need to provide IS893(Part-1)-2016 seismic definition. STAAD.Pro CE has been designed to compare Vb/VB internally and if VB> Vb, all the response quantities will be amplified by (Vb/VB) factor by the program. Hence, one must provide a IS893(Part-1)-2016 seismic definition while performing IS1893 Response Spectrum Analysis.