There is currently no efficient way to consider the live load reduction factor in STAAD.Pro. It would be fantastic to add a parameter to the design section (e.g., under CSA S16-19 or AISC 360-16) to consider a live load reduction on an element by element basis. This would be manually calculated by the analyst until someone at Bentley can figure out how to determine tributary area for an element based perhaps on the floor load command (easy example for columns, TA = axial load/input floor live load; for girders, TA = [shear 1 + shear 2] / input floor live load).