تحلیل روش های پایدار محیط زیست برای استفاده زودتر در چرخه عمر محصول Analyzing environmental sustainability methods for use earlier in the product lifecycle

1. INTRODUCTION Manufacturing has a large impact on the environment, including high energy consumption, waste generation, and greenhouse gas emissions. Energy consumption in the manufacturing industry rose approximately 3.7 % from 2010 to 2014 from 5.38 billion kWh to 5.58 billion BTU [1]. This marked the first time since 2002 that energy consumption had risen in a four year period in the industrial sector. On top of this, American industrial facilities generate 7.6 billion tons of waste annually [2] and accounted for emissions of 6.587 billion metric tons of carbon dioxide (CO2) equivalent [3] in 2015. This represented 21 % of all 2015 greenhouse emissions in the US, with transportation contributing 27 % and electricity production contributing 29 %. Considering the downstream manufacturing supply chain, which is larger than the manufacturing industry in itself and includes transportation and electricity generation among other considerations [4], manufacturing accounts for more than half of the total environmental impact of the US economy [5]. To reduce the impact that manufacturing has on the environment, a variety of methods are deployed at multiple stages of the product lifecycle. For example, to reduce energy usage during production, the Environmental Protection Agency (EPA) created the energy star program for industrial energy management in 1992 [6]. Through this program, General Motors (GM) reduced energy consumption by 40 % and CO2 emissions by 41 % over 20 years while simultaneously increasing productivity [7]. This is a savings of over $435 million for their manufacturing plants, which make up 75 % of all energy consumed at GM. One area where GM was able to save energy was through the “Shut It Off” campaign where non-essential, energy intensive equipment was switched off while not in use [8], but this effort was only focused on the production stage of the product lifecycle. Less explored opportunities for environmental impact reduction still remain when manufacturing knowledge is readily available to designers during product design. For example, if a manufacturing process for a part feature is energy intensive, a product designer might consider an alternative feature that requires a less energy intensive process and still meets specifications. Lifecycle Assessment (LCA) practitioners often ignore impacts from manufacturing in certain scenarios since the resultant magnitudes of impact are often less than cut-off values of the analysis, making manufacturing impacts seem insignificant compared to the rest of the lifecycle; however, this practice can be short sighted.