“…The approach could support a holistic and structured way to understand and formulate problems in biorefineries, enabling a variety of solution methods and engaging links between different models. As illustrated in Figure 9, the approach could stratify problems formulated over different levels (scales), echoing similar multi-level and multiscale paradigms in the literature (Marquardt et al, 1999;Pantelides, 2001;Grossmann, 2004;Ingram, Cameron & Hangos, 2004). At the scale of a preliminary strategic investigation (or business conception), issues would address the regional planning and the evaluation of processing paths in combination with feedstock portfolios and logistics.…”