Product development is accomplished through a plurality of product development tools, each tool assisting in a separate aspect of product development. The invention also proposes a device suitable for performing the aforementioned method, in which the tool and a tool tip, during workpiece machining, are movement-controllable by the manipulator control unit. A connecting channel extends through the manifold and connects a high-pressure exhaust gas outlet) of the high-pressure turbine housing with a low pressure exhaust inlet) of the low pressure turbine housing. The method can give a copolymer high in solubility and suitable for the processing by the flush vacuum dry system, and the method is excellent from the standpoint of the production capacity and stablesafe production throughout the process.