This article discusses the ORWARE tool, a model originally developed for environmental systems analysis of waste management systems, and shows its prospect as a tool for environmental technology chain assessment. Different concepts of technology assessment are presented to put ORWARE into context in the discussion that has been going for more than two decades since the establishment of the US Congressional Office of Technology Assessment (OTA). An even-handed assessment is important in different ways such as reproducibility, reliability, credibility, etc. Conventional technology assessment (TA) relied on the judgements and intuition of the assessors. A computer-based tool such as ORWARE provides a basis for transparency and a structured management of input and output data that cover ecological and economic parameters. This permits consistent and coherent technology assessments. Using quantitative analysis as in ORWARE makes comparison and addition of values across chain of technologies easier. We illustrate the application of the model in environmental technology chain assessment through a study of alternative technical systems linking waste management to vehicle fuel production and use. The principles of material and substance flow modelling, life cycle perspective, and graphical modelling featured in ORWARE offer a generic structure for environmentally focused TA of chains and networks of technical processes. (C) 2004 Elsevier Ltd. All rights reserved.
