Determining the Indicators of Sustainability Essay
The DSS for construction materials selection has to consider indicators of sustainability of construction materials with respect to the three global objectives of sustainable development – resource consumption, human satisfaction and environmental impact. The more exhaustive the list of indicators, the more the DSS will tend towards perfection.Indicators could be as varied and wide ranging as the scale on which the harvesting is done, whether infrastructure for harvesting is available, how accessible the raw materials are, the extent of processing the material has to be out through, how renewable the materials, maintainability, toxicity, market pricing of comparable resources, etc. Each indicator has to be correlated with the sustainability of the material, and the correlation determined through sensitivity analysis and indexed and rated so that comparison of the materials is possible to the minutest details.
Selection of indicators of sustainability of the materials therefore assumes great importance in any DSS. Database or knowledge base development in this respect has to systematic and incremental throughout the development cycle. Consideration of the context of use also holds equal importance in the determination of sustainability of any construction material. Contextual indicators could be as apparent as the availability and use of ice blocks in the poles and sand in the deserts. But these indicators could also be user specific, condition specific or site characteristic specific.
Context modifiers therefore have to be built into any DSS. It is the context modifiers that make the sustainability ratings of construction materials for each project unique. Decision makers set threshold values in heuristics databases which enable them to specify the values that they want to be calculated. Edwards et al. (1994) and Greene (1994) give examples of techniques in transportation systems in which the energy required to transport a particular material from one place to another for various modes of transport can be calculated for different modes or types of transport.