This invention concerns apparatus for generating instructions for machines of a manufacturing chain used to manufacture a workpiece. The apparatus comprising a processor arranged to receive a model based definition (MBD) of a workpiece including geometric dimensions and tolerances; receive inputs setting an additive build design for building the workpiece based upon the geometric dimensions; generate additive instructions for an additive manufacturing machine of the manufacturing chain based upon the additive build design; determine a prospective intermediate workpiece product expected from an additive build in accordance with the additive build design; determine differences between the prospective intermediate workpiece product and the model based definition of the workpiece; and generate further instructions for at least one further machine of the manufacturing chain based upon the differences.

Systems and methods for virtual machine management are disclosed. A virtual machine manager may communicate with a storehouse, which may include one or more virtual machines. The virtual machine manager may select one or more virtual machines, or may create one or more virtual machines, depending on the requirements of an input.

There is a stack visualization method using a stack visualization apparatus including a deposition head. The method comprises collecting a moving speed of the deposition head; collecting laser power information of the deposition head by which a laser is irradiated to a stack; selecting a virtual stack corresponding to the moving speed of the deposition head and the laser power information among a plurality of previously stored virtual stacks based on the moving speed of the deposition head and the laser power information; and visualizing the selected virtual stack through a digital twin model.