When handling, multivariate impacts analysis, i.e. in acknowledging multiple incommensurable dimensions, any decision making process requires a step of value judgement declaration. We first present the evolution context of the methodology and stress out the stratification of science as a major obstacle. Here is presented an extension of allocation systems based on \textsc{Majeau-Bettez} formalism in order to integrate multi-criteria allocation. The use of a hierarchy process on allocation keys enable to treat multi-functionality according to decision makers preferences. This enable the allocation between valued co-products of distinct attributes. The process of elicitation and implementation of values should grant legitimacy to the use of LCA and the way t will be performed will reflect our cultural portrait. Our perspective is to develop this model to integrate all value judgements required in LCA. Thus we would provide a tool for a complete agent based LCA-modelling. Perspective are complemented in annexes with the communication protocol proposed to lighten the data availability issue.