Simplified conceptual diagram of the main issues of system experiments in agronomy. Experimental design must be conducted in accordance not only with agronomic questions, but also with relevant analyses (1). At each step, the identification of methodological issues (2) and their resolution (3) enables reliable analyses (4) that can lead to new agronomic questions (7). When carrying out data analyses, new methodological issues may arise (5) and require adaptations (6).