Supplier capability assessment as a tool for product and process optimization

The Compact Linear Collider (CLIC) project is testing accelerating structure prototypes made of Oxygen Free Electronic (OFE) Copper. CLIC is looking to optimize the design and to reduce the manufacturing cost towards mass production. The fundamental unit, a disc of 83 mm, has sub-micrometre tolerances and therefore requires ultra-precision diamond turning and milling. This paper presents supplier's process capability on the production of four accelerating structures (118 parts). Moreover, these measurements together with a sensitivity analysis allow us to identify non-significant design parameters that were relaxed in a second production batch (138 parts). The changes on the design did not affect the accelerating capacity and reduced the unit price of 25%. The supplier performance of the second batch showed the expected good results.