Additive manufacturing (AM) is a process in which a three-dimensional object is built from a computer-aided design (CAD) model, usually by successively adding material in a layer-by-layer fashion. AM is different from conventional manufacturing processes (such as machining, casting and forging) where material is removed from a block or injected into a mold to form the product and detailed process planning must be made to determine machining steps to obtain the physical geometries. With AM there are no limits in terms of design, geometrical complexity of the components no longer impedes the process (hollow features, assembly consisting of several components). Obviously some constraints remain (e.g., overhang and build size) but parts can generally be made according to the design that best fulfills their function.