An assembly for debulking an uncured stack of plies of fiber reinforced composite material, comprising: a force application element for application of force onto the uncured stack of plies of fiber reinforced composite material positioned on a forming tool; and a heat source, associated with the force application element, wherein the heat source is positioned, in at least one of a following position: spaced apart from a top ply of the uncured stack of plies of fiber reinforced composite material to directionally heat the uncured stack of plies of fiber reinforced composite material from the top ply, in a direction toward the forming tool, through a bottom ply of the uncured stack of plies of fiber reinforced composite material; with the forming tool positioned between the heat source and the uncured stack of plies of fiber reinforced composite material, the heat source to heat the forming tool, to directionally heat the uncured stack of plies of fiber reinforced composite material in a direction from the bottom ply through the top ply of the uncured stack of plies of fiber reinforced composite material; or between the uncured stack of plies of fiber reinforced composite material and the forming tool to directionally heat the uncured stack of plies of fiber reinforced composite material in the direction from the bottom ply through the top ply of the uncured stack of plies of fiber reinforced composite material, wherein the force application element includes a roller having a longitudinal axis, wherein the roller defines at least two openings, which extend along the longitudinal axis of the roller, whereby the roller is constructed of rubber or various elastomeric materials. a force application element for application of force onto the uncured stack of plies of fiber reinforced composite material positioned on a forming tool; and a heat source, associated with the force application element, wherein the heat source is positioned, in at least one of a following position: spaced apart from a top ply of the uncured stack of plies of fiber reinforced composite material to directionally heat the uncured stack of plies of fiber reinforced composite material from the top ply, in a direction toward the forming tool, through a bottom ply of the uncured stack of plies of fiber reinforced composite material; with the forming tool positioned between the heat source and the uncured stack of plies of fiber reinforced composite material, the heat source to heat the forming tool, to directionally heat the uncured stack of plies of fiber reinforced composite material in a direction from the bottom ply through the top ply of the uncured stack of plies of fiber reinforced composite material; or between the uncured stack of plies of fiber reinforced composite material and the forming tool to directionally heat the uncured stack of plies of fiber reinforced composite material in the direction from the bottom ply through the top ply of the uncured stack of plies of fiber reinforced composite material, wherein the force application element includes a roller having a longitudinal axis, wherein the roller defines at least two openings, which extend along the longitudinal axis of the roller, whereby the roller is constructed of rubber or various elastomeric materials. spaced apart from a top ply of the uncured stack of plies of fiber reinforced composite material to directionally heat the uncured stack of plies of fiber reinforced composite material from the top ply, in a direction toward the forming tool, through a bottom ply of the uncured stack of plies of fiber reinforced composite material; with the forming tool positioned between the heat source and the uncured stack of plies of fiber reinforced composite material, the heat source to heat the forming tool, to directionally heat the uncured stack of plies of fiber reinforced composite material in a direction from the bottom ply through the top ply of the uncured stack of plies of fiber reinforced composite material; or between the uncured stack of plies of fiber reinforced composite material and the forming tool to directionally heat the uncured stack of plies of fiber reinforced composite material in the direction from the bottom ply through the top ply of the uncured stack of plies of fiber reinforced composite material, wherein the force application element includes a roller having a longitudinal axis, wherein the roller defines at least two openings, which extend along the longitudinal axis of the roller, whereby the roller is constructed of rubber or various elastomeric materials.