floors slab stiffness in a staad model

how would you intoduce the stiffness of a floor slab in 3D staad model for a building subjected wind/ seismic loading? i know you could use elements to model the slabs, but is there any other way to do so.

 

[sbp]

hi.
Modelling the slab with plate element, though accurate, would be tedious. STAAD has one nice provision for this in MASTER SLAVE constraint. Use this constraint to account for slab rigidity without modelling the slab.