AT&T developed an abridged matrix approach for LCA to facilitate semi-quantitative, efficient assessments of complex manufactured products or industrial manufacturing processes. This is in recognition of the complexities of a complete LCA coupled with the difficulties in relating inventory analysis to impact and improvement analysis. The abridged approach attempts to allow firms to do rapid LCAs, for example, 2 days for a typical product or one week for a typical facility.
The matrix uses a scoring system for comparing options while focusing on those design and implementation aspects whose modification could most dramatically affect the rating. Five life-cycle stages are taken into account:
Stage 1 | Premanufacturing | |||
Stage 2 | Manufacturing | |||
Stage 3 | Product delivery (including installation) | |||
Stage 4 | Customer stage | |||
Stage 5 | Termination of product's life |
Each stage is controlled by different parties, for instance, the customer stage is not directly controlled by the manufacturer, but is influenced by how products are designed. A 5 x 5 assessment matrix , called the Environmentally Responsible Product Assessment Matrix, is recommended. One dimension is the life-cycle stage, and the other is the environmental concern. The ratings are from 0 (lowest impact) to 4 (highest impact), with higher numbers reflecting more positive evaluations. The assessment is subjective and the assessors need to have adequate information to allow comparative ratings and evaluations on a variety of characteristics. For example, products can be compared against materials choice, energy use, solid residue, liquid residue, and gas residue, in each of the life-cycle stages. According to some AT&T evaluations, these informal assessments vary only slightly among different groups of assessors. The matrix approach can be made more detailed by applying weighting factors to the matrix elements.
This approach does not take cost considerations into account, nor does it consider all the environmental impacts. The subjective nature of the evaluations will cause some value judgments and the accuracy of the assessment is dependent on the expertise and knowledge of the assessor(s). However, the approach does provide organizations with an approach to take to account environmental considerations that would otherwise be ignored.
The description of the model can also be found in a textbook called 'Industrial Ecology' by Tom Graedel and Brad Allenby. This book is available for $37 from Prentice Hall Publishing (515-284-6761), ISPN0-13-125238-0.
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