On-Site or Off-Site Additive Manufacturing Spare Parts Production? An Economic and Environmental Analysis Encompassing Country Carbon Tax Policy, Energy Mix, and Availability
研究了在增材制造备件生产中，现场生产是否总是优于场外生产，发现当场外单位能源成本更低时，场外生产在经济和环境上更优，且当前碳税水平下决策仅由经济因素驱动。
Additive Manufacturing (AM) has been extensively studied for spare parts management. The literature concurs that producing AM spare parts close to the point of use (i.e., on-site) offers both economic and environmental advantages compared to off-site production, particularly when spare parts are produced through printing hubs, which is the current industrial practice. However, this might not always hold true: different countries have different energy costs and emit different amounts of CO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-eq</sub> to produce one kWh. Consequently, it may be preferable to produce spare parts in a country having low energy costs and/or depending less on fossil fuels, even if far from point of use (i.e., off-site). Such decisions should also consider governmental carbon-reduction schemes (e.g., carbon taxes) whereby the more a firm emits, the more it pays. However, there is a lack of research encompassing all these aspects when deciding whether to produce AM spare parts on- or off-site. This work fills this gap, identifying if and when off-site production of AM spare parts is preferable from both economic and environmental perspectives. Contrary to claims in the literature, the results show that off-site production is sometimes preferable, particularly when its unitary energy cost is lower than that of on-site production. Interestingly, due to current low carbon tax values, the on-site/off-site production decision is driven only by economic considerations. Robustness checks confirmed the findings' reliability. Notably, adopting off site AM production, when advantageous, results in substantial savings, as demonstrated numerically and through a case study considering 6,000+ spare parts.