Qualitative Life Cycle Assessment

Life Cycle Assessment (LCA) describes the process of evaluating the environmental impacts of a product at each stage of its life and overall. While full LCAs can be intensively data-driven, as will be described in the following section, sometimes a qualitative assessment is all that is required. This is often called a Qualitative LCA or a Qualitative Matrix LCA.

 

Such evaluations can be used as stand-alone decision tools, but often they serve to identify the design options worth more detailed analysis. Evaluations can be text-based or scored, but there are no standard axes or rating systems so organizations can adopt whatever metrics work for their purposes. This figure shows an example of one such matrix used by 3M.[1]

 

 

Evaluation approaches become even more effective when adopted by more than one company, or even by a whole industry. One example of this is the apparel industry’s Eco Index, created through the collaborative efforts of over 100 producers and retailers and coordinated by the Outdoor Industry Association.[2] The resulting software application guides its users through a set of questions for each of six life cycle stages, focused on seven key areas of impact.[3] 

 

 

The scoring system is based on points awarded based on meeting various criteria. For example, in the Packaging area, Post Consumer Recycled (PCR) Content scores range from 0 for “unknown or 0-29% post consumer recycled content” to a maximum of 8 for 100% PCR content. Such scoring systems try to reflect the scale of impact somewhat quantitatively, although the direct impact of changes is hard to see. The scorecard’s guidelines state that use of PCR leads to resource conservation such as less energy used, less waste produced, and less virgin raw material extracted, but does not say how much. Therefore, it is not easy to tell whether it makes a big or small difference changing from, say, 29% PCR to 30% PCR to get an extra point on the scorecard, something product designers may want to know. Plus, a one point change due to PCR use may have very different environmental impacts than a one point change in raw material input use efficiency. Results are in the form of points, not impacts.

 

Qualitative impact assessments tend to be quicker, less expensive, and easier for non-specialists to participate in and understand than quantitative ones. Their lack of precision can be acceptable for many high-level decisions, or for indicating when it is worth investing the time and effort required to generate a more detailed understanding of the environmental impacts that many quantitative methods can provide.

 

Qualitative LCA and the Three Choices

 

1. Impacts – Any
2. Scope – All life cycle stages
3. Metrics – Generally scores 

 

 

 

 

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