The result of productive processes is commonly accompanied by a set of justifications which can be, depending on the product, process-related qualities, traceability documents, product-related experiments, tests or expert reports, etc. In critical contexts, it is mandatory to substantiate that a product's development has been carried out appropriately which results in an inflation of the quantity of justification documents. This mass of document and information is difficult to manage and difficult to assess (in terms of soundness). In this paper, we report on the experience gained on two industrial case studies, in which we applied a justification elicitation approach based on justification diagrams and justification pattern diagrams in order to identify necessary and sufficient justification documentation.