The impact of direct digital manufacturing on supply chain operations, cost and environmental performance in an aerospace application

Industry 4.0 concepts, such as direct digital manufacturing (DDM), are expected to change the world, the society and the industry within the coming decades. This study explores the potential implications of DDM on supply chain operations by performing a case study. It assesses the impact of distributed production capabilities enabled by additive manufacturing (AM) on the life cycle cost and environmental impact in an aerospace application. It builds on a previous life cycle assessment (LCA) conducted by GE to compare the environmental impacts of using fuels nozzles produced via additive and conventional manufacturing over a future period of 30 years. Here, simulation models are developed to represent the aftermarket of the LEAP engine based on current and forecasted airline fleets for US and Canadian airline operators. Three supply chain operation scenarios are considered: (1) conventional manufactured at a central GE manufacturing plant at a high volume; (2) additive manufactured, high-volume at the same plant; and (3) de-centralized, low-volume, additive manufactured at 7 identified demand locations. 648 experiments were run to capture all relevant combinations of service levels, electricity mix, carbon pricing, and electric truck adoption. Production, distribution, and energy consumption were simulated based on information from publicly available sources. Environmental impacts on resource availability, climate change, human health and ecosystem quality were assessed using an integrated hybrid LCA model developed by the United States (US) Department of Defense (DOD). Data-envelopment analysis was used to benchmark the supply chain operation systems based on their cost, environmental and supply chain performance. Both additive production systems show stronger efficiencies than the traditional manufacturing system. The de-centralized system benefits from its flexibility and locations that already contain high amounts of renewable energy highlighting the significance of the site selection process. The centralized system requires inventory to be competitive but shows benefits due to economies of scale and strategic investments that would not be justified for smaller facilities. The applied methodology has shown plausible results over all experiments and can therefore be recommended for decision makers from private and public sectors for benchmarking their alternatives when considering cost and environmental criteria