In this paper, the development and the advantages of a methodology which allows the systematic assessment of the environmental impact on the resource side of specific pharmaceutical production processes with limited data entry is presented. The quantification of the process-specific mass and energy balances over three different system boundaries (process, gate-to-gate, and cradle-to-gate) is based on the methodology explained in Van der Vorst et al. (Ind. Eng. Chem. Res.2009, 48(11), 5344-5350). These mass and energy balances are now coupled with the thermodynamic term exergy allowing the quantification of the resource efficiency at the process and gate-to-gate level and the environmental impact at the cradle-to-gate level. The advantages of such a calculation tool for the resource evaluation are illustrated with five consecutive pharmaceutical production steps which are part of the galantamine (anti-Alzheimer medication) pathway. It is shown that such a quantitative and systematic evaluation tool allows a detailed and relatively fast evaluation of the resource efficiency of active pharmaceutical ingredient (API) production processes at the three different levels. Combining thermodynamics and the systematic data inventory methodology for the quantification of the resource efficiency first allows results to be merged into a single impact value (exergy loss/mol API or CEENE/mol API) for fast benchmarking and evaluation of different API production processes. Second, it also allows results to be divided over different categories depending on the users' interest and make thorough analysis of processes in order to pinpoint process improvements and quantitatively justify the introduction of second generation production processes or production techniques.