Production Scheduling in Complex Job Shops from an Industrie 4.0 Perspective: A Review and Challenges in the Semiconductor Industry

On the one hand, Industrie 4.0 has recently emerged as the keyword for increasing productivity in the 21st century. On the other hand, production scheduling in a Complex Job Shop (CJS) environment, such as wafer fabrication facilities, has drawn interest of researchers dating back to the 1950s [65, 18]. Although both research areas overlap, there seems to be very little interchange of ideas. This review presents and assesses production scheduling techniques in complex job shops from an Industrie 4.0 perspective. Based on the literature review, the authors' experience in the semiconductor industry and feedback and discussions with industry experts, this paper identies challenges in production control. We identify four future directions: Decentralization and autonomous decisions, exibility and adaptability, integration and networking and human aspects in an environment with rising complexity. While this review and certain challenges are motivated by semiconductor fabrication plants, the paper serves as a general overview of the state-of-the-art in job shop scheduling

Effect of preparation conditions of Au-Mn co-precipitates for low temperature CO oxidation

Au-Mn co-precipitates were dried at different tempertures and in different atmospheres. The co-precipitates were tested for low temperature CO oxidation without any additional thermal treatment. While a sample dried at 120 ℃ in air exhibited the highest activity for oxidation of CO, samples dried at room temperature under vacuum were less active. This result indicates that high-temperature and air drying can affect catalyst performance favourably. The catalytic properties of most fresh samples improved after the first light-off test, during which a temperature of 400 ℃ was reached. To investigate the physical and chemical state of gold and substrate, dried samples were examined by Au Mössbauer spectroscopy, x-ray diffraction (XRD) and transmission electron microscopy (TEM). Au Mössbauer spectra showed that gold existed only in metallic form, even for samples dried at room temperature. XRD analysis demonstrated that fresh samples contained a large amount of manganese carbonate. The carbonate converted to manganese oxides after the light-off test. TEM analysis indicated that the manganese substrate was present in plate-like and needle-like shapes and the shape of gold particles was elliptical or rectangular with rounded corners. The results show that the conditions of drying have a significant effect on the performance of Au-Mn co-precipitates

Developing a framework for virtual metrology and predictive maintenance

The implementation of novel APC techniques in semiconductor fabs calls for cooperative development. A barrier for sustainable joint activities is often the variety of fab infrastructures at different partners. Thus, in the ENIAC project IMPROVE, a fabwide framework was developed to support the research of reusable APC components. This article describes the concept and integration examples of the framework