Managing variability within wafertest production by combining lean and six sigma

Manufacturing organization in the manner of flow production is one of the best solutions to achieve short cycle times, low inventories and a high delivery reliability, which are vital for commercial success. Variability within all production, support and organizational processes is one of the main detractors for establishing a continuous material flow in semiconductor manufacturing. In this contribution an approach for identification, classification, observation, reduction, mastering and even elimination of variability is shown. This is done by combining elements as well as tools of lean manufacturing and six sigma. The approach is validated by a case study in a wafertest environment and enables establishing the Virtual Time based Flow Principle.