A system for incrementally forming a composite part, the system comprising: a forming mandrel that includes a forming surface, wherein a surface profile of the forming surface corresponds to a surface profile of the composite part, and further wherein the forming surface is configured to receive a ply of composite material; and a forming machine including: (i) a forming bladder that defines an internal volume; (ii) a pressure-regulating device configured to regulate a pressure within the internal volume; and (iii) a positioning device configured to selectively position the forming bladder relative to the forming surface at a plurality of selected locations; wherein the forming bladder is configured to be inflated to a forming pressure and to selectively and operatively press the ply of composite material against the forming surface at each of the plurality of selected locations to conform corresponding portions of the ply of composite material to the surface profile of the forming surface and at least partially define the composite part; wherein the positioning device is configured to operatively translate the forming bladder relative to the forming mandrel along a length of the forming mandrel; wherein the forming machine further includes a controller programmed to control the operation of at least one of the pressure-regulating device and/or the positioning device; wherein the forming surface is configured to receive a plurality of stacked plies of composite material to define the composite part; and wherein the forming bladder is configured to sequentially press each of the plurality of stacked plies of composite material against the forming surface. a forming mandrel that includes a forming surface, wherein a surface profile of the forming surface corresponds to a surface profile of the composite part, and further wherein the forming surface is configured to receive a ply of composite material; and a forming machine including: (i) a forming bladder that defines an internal volume; (ii) a pressure-regulating device configured to regulate a pressure within the internal volume; and (iii) a positioning device configured to selectively position the forming bladder relative to the forming surface at a plurality of selected locations; (i) a forming bladder that defines an internal volume; (ii) a pressure-regulating device configured to regulate a pressure within the internal volume; and (iii) a positioning device configured to selectively position the forming bladder relative to the forming surface at a plurality of selected locations; wherein the forming bladder is configured to be inflated to a forming pressure and to selectively and operatively press the ply of composite material against the forming surface at each of the plurality of selected locations to conform corresponding portions of the ply of composite material to the surface profile of the forming surface and at least partially define the composite part; wherein the positioning device is configured to operatively translate the forming bladder relative to the forming mandrel along a length of the forming mandrel; wherein the forming machine further includes a controller programmed to control the operation of at least one of the pressure-regulating device and/or the positioning device; wherein the forming surface is configured to receive a plurality of stacked plies of composite material to define the composite part; and wherein the forming bladder is configured to sequentially press each of the plurality of stacked plies of composite material against the forming surface.