AbstractThis paper combines theoretical sustainable business models and conflict indices in making practical sustainable (i.e., participatory decisions involving economic, social, and environmental features within weak or strong sustainability paradigms) and rational (i.e., informed and consistent decisions within substantive or instrumental rationality) decisions with respect to what, who, where, when, and how to act. The case study, focused on an offshore gas platform, identified when (i.e., the end as opposed to the beginning of extraction activities) and where (i.e., the economic, social, and environmental contexts of the Adriatic Sea in Abruzzo region, Italy). A face‐to‐face questionnaire, submitted to stakeholders, produced the relative weights required by the tested sustainable business models (Lüdeke‐Freund et al., 2018), and it reached a conclusion about how (i.e., in favor of the majority as opposed to average decisions). An application of a linear conflict index (Fasth et al., 2018) highlighted a lack of stakeholders' representativeness and knowledge and solved these issues with a 50% increase of stakeholders involved and an additional discussion with originally invited stakeholders on specific topics, respectively. In summary, the methodology suggested in this paper produced a (strong) sustainable and (substantive) rational decision about what and who based on relative weights expressed by representative and informed stakeholders being engaged at the smallest cost and with the largest support. Thus, the contribution of this paper is twofold: Theoretically, choices among alternative sustainable businesses depend on the adopted sustainability paradigm, and practically, choices among alternative sustainable businesses should be identified according to the adopted sustainability paradigm.