A method executed at least partially by a processor includes determining a power parameter associated with a cell in an integrated circuit (IC) layout diagram. In response to the determined power parameter exceeding a design criterion, the method further includes performing a modification of the IC layout diagram, the modification including at least one of altering a placement of the cell in the IC layout diagram or modifying a power delivery path to the cell. The determining the power parameter is performed before a routing operation in the IC layout diagram.