This article discusses the comparability of Life Cycle Assessments (LCAs) and the central role of the application purpose in a study review. According to ISO 14040, an LCA study design emerges in continuous reference to the “intended application”. Goal and scope, case-specific assumptions, as well as methodological freedoms, should be justified by their significance for the specific application purpose, e.g. for process optimization or for advice on a political issue. In contrast, our systematic review of 58 LCA studies shows that LCAs hardly name applications, and more generally, applications are difficult to reconstruct. This lack of transparency makes the LCA methodology attackable through meta-studies that ignore the problem-oriented and case-specific approach. Since these studies are valuated for different purposes by a diverse set of actors, quantification in any study that does not represent the context and purpose of its generation can disguise as much as it can enlighten. Therefore, we propose what a study should look like that is problem-solving, concrete and yet provides transferable results for other studies.