As a decision support tool, life cycle assessment (LCA) is prone to multiple uncertainties associated with the data, model structures, and options offered to practitioners. Therefore, to make the results reliable, consideration of these uncertainties is imperative. Among the various classifications, parameter, scenario, and model uncertainty are widely reported and well-acknowledged uncertainty types in LCA. There are several techniques available to deal with these uncertainties; however, each strategy has its own pros and cons. Furthermore, just a few of the methods have been included in LCA software, which restricts their potential for wider application in LCA research. This paper offers a comprehensive framework that concurrently considers parameter, scenario, and model uncertainty. Moreover, practitioners may select multiple alternatives depending on their needs and available resources. Based on the availability of time, resources, and technical expertise three levels—basic, intermediate, and advanced—are suggested for uncertainty treatment. A qualitative method, including local sensitivity analysis, is part of the basic approach. Monte Carlo sampling and local sensitivity analysis, both of which are accessible in LCA software, are suggested at the intermediate level. Advanced sampling methods (such as Latin hypercube or Quasi-Monte Carlo sampling) with global sensitivity analysis are proposed for the advanced level.

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The development of new bio-based diesel substitutes can improve their compatibility with diesel engines. Nevertheless, for actual implementation, their environmental and economic performance needs to be studied. This study quantified the eco-efficiency of three bio-based diesels, viz., fatty acid methyl ester (FAME), partially hydrogenated FAME (H-FAME), and bio-hydrogenated diesel (BHD), to address the perspective of producers as well as policymakers for implementing the advanced diesel alternatives. The eco-efficiency was assessed as a ratio of life cycle costing as the economic indicator and three different environmental damages—human health, ecosystem quality, and resource availability. The eco-efficiency of FAME was the most favorable among all the potential substitutes with regard to human health and ecosystem quality, but the least favorable for resource availability impact. Even though BHD was beneficial in terms of life cycle costing, it was the least preferable when considering human health and ecosystem quality, though it performed the best for resource availability. H-FAME was also promising, in line with FAME. It is suggested that the technologies for BHD production should be improved, especially the catalyst used, which contributed greatly to environmental impacts and costs.