Biotechnology is applied in many industrial areas and uses microorganisms, enzymes, or precursors replacing chemicals to produce goods, including chemicals, plastics, food, agricultural and pharmaceutical products, and energy carriers from renewable raw materials and increasingly also from waste from agriculture and forestry (BIOPRO Baden-Wurttemberg GmbH, Facts and Figures. Biotechnologie.de. https://www.biooekonomie-bw.de/en/articles/dossiers/industrial-biotechnology-biological-resources-for-industrial-processes/, 2013). In comparison with conventional processes, industrial biotechnology processes often run under relatively mild reaction conditions, moderate temperatures, and the use of aqueous media. They might reduce in general the energy requirements and the number of by-products. Since product concentration and formation rate are often very low, the resulting products need to be purified and recovered in marketable quantities in a process that is referred to as downstream processing. Product quantity can also be increased by optimizing the manufacturing processes or biocatalysts used (OECD, the application of biotechnology to industrial sustainability. www.oecd.org/sti/biotechnology, 2001). In this context, developing a sustainable bio-based economy that uses ecoefficient processes is one of the key strategic challenges for the twenty-first century. Decisions in the technology development are often supported by sustainability assessment results using different types of sustainability assessment methods. In the last decades, we developed different types of sustainability assessment methods evaluating aspects of economy, ecology, and society to support decision-making processes. We show in this chapter how different types of questions can be answered, how more sustainable solutions can be identified, and how this information can be used for marketing and research activities. [GRAPHICS] .