Tuesday, September 3, 2013

LCA v DfE, An alternative View

I would like to discuss an alternative viewpoint of the role of Life Cycle Assessment and Design for the Environment than that presented in "Design for the Next Generation: Incorporating Cradle-to-Cradle Design into Herman Miller Products," specifically with the view of motivation for innovation in supply change management.

It is true that the impacts evaluated in published LCAs tend to be those related to cumulative energy demand and carbon-footprint, while those of DfE (as presented in this paper) are focused on human and biological environmental health. In this way, LCA takes a more global (climate change) view of hazards than some other evaluation methodologies (ecosystem damage and resource depletion).

Note that the DfE process here, although dependent upon supply change and engineering changes, is largely focused on reducing downstream impacts, activities that are often out of the manufacturers control. The usefulness of the recyclability of the materials used depends on the consumer's willingness to put them into into the recycle loop. DfE does emphasize design for disassembly, but this has been most effective when used in conjunction with remanufacturing and refurbishing processes that allow the materials to be reused in a similar or repaired product. Remanufacturing requires development of new networks and systems and has been most effective with machinery and modular construction.  In "Reduce Reuse Recycle", recycling is the least preferred option of the three (especially keeping in mind that most plastics can only be down-cycled-- ground up and used for fill material in other products).

LCA, on the other hand, provides an opportunity to address the first option- reduce. Decision related to drawing a system boundary and weighting the impacts does have the ability to introduce bias into the results. However, a well-done LCA-- whether with very specific process data (often not published because it is proprietary) or with average data-- can identify processes and materials with the largest energy demand and therefore, the greatest potential for cost saving though energy reduction efforts. Identifying high energy use can drive financial decision to implement more efficient technology or simply implement best practices in operation. Furthermore, LCA that incorporate economic input-output tables (though they have limitations in drawing conclusions for comparative LCAs) have the ability to pin-point sectors in the supply chain with large economic transactions. Businesses may find this more useful than DfE because it can be used to again identify an opportunity to find ways to save money, and reduce the use of material and energy at the start, rather than simply try to get the most out of it later.

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