A method of defining a composite tape course to form at least a portion of a composite part ply comprises approximating a contoured surface with a reference plane. The method further includes selecting a three-dimensional reference surface to approximate the contoured surface and defining a first function to correlate a first point from the contoured surface to a first intermediate point on the reference surface. The method includes selecting the reference plane to approximate the reference surface, defining a second function to correlate the first intermediate point to a reference point in the reference plane, and mapping a ply boundary from the contoured surface to a reference ply boundary in the reference plane. A tape boundary may be mapped from the contoured surface to a reference tape boundary in the reference plane. A tape edge may be defined based at least in part on a reference intersection of the reference ply boundary and the reference tape boundary in order to form at least a portion of the composite part ply using the defined tape edge.