Different decision analysis tools (e.g. risk assessment (RA) and cost benefit analysis (CBA)) are applied in different research areas to help decision makers choose the favorable alternatives based on their associated consequence or impacts. Considering the variety of decision problems to be answered, the consequences that are of decision makers concerned are not uniform. These different consequences are thus described by divergent indicators and their corresponding metrics. Due to lack of concern on environmental impacts, consequences on environmental impacts are rarely addressed in those decision analysis tools. LCA, as a robust tool for environmental impact assessment, has a strong potential to be integrated with other decision analysis tools to fill this gap. However, the environmental impacts assessed by LCA are expressed in metrics that is not identical to the ones in other decision support tools. Thus there is a need for harmonizing the metrics in LCA and other conventional decision analysis tools before they can be used together for alternative optimization. The methodologies that deliver numbers to fit into the metrics are the driven force for the harmonization. Therefore, the uncertainty associated with those methodologies, especially LCA will also be addressed.