Manufacturing variability drives significant environmental and economic impact: the case of carbon fiber reinforced polymer composites in the aerospace industry

Abstract The link between manufacturing variability and the resulting environmental impact is an understudied topic. We connect manufacturing variability and greenhouse gas emissions impact through the reality of overdesign. Specifically, this study takes the case of manufacturing Carbon Fiber Reinforced Polymers, which has high manufacturing variability relative to conventional manufacturing process and is of interest to due to its light-weighting potential. Through the use of a process-based cost model, including uncertainty through a simulation, the cost and energy required to fabricate a representative composite part is modeled. The model then connects to a fuel-consumption model of a Boeing 787 which allows the estimation of lifetime fuel savings. Manufacturing variability is taken as an input to the model, which allows the model to estimate the effect of variability on both the cost and energy requirements. We find that manufacturing variability has significant impact on both part cost and energy requirements, being the fourth most impactful variable in our model for both these performance measures. Under our assumptions, reducing the coefficient of variation of the mechanical properties from 14% to 9% reduces production costs and energy by 12.3 and 11.8% respectively. In addition, due to the weight savings, we estimate that over the lifetime of a Boeing 787 this drop in variability saves 8.3 kton of fuel, which has a present value of 3.6 million USD and would prevent 21.9 kton carbon dioxide from entering the atmosphere.