The evaluation of sustainability is complex, involving several factors and expert opinions. In our research, we analyzed and evaluated the activities of a premium packaging material manufacturer with the participation of three relevant and professional groups. Various expectations have been defined in the form of plan values. From these plan values, we measured and evaluated the sustainability level of the company with the help of plan-fact ratios, fuzzy logic and triangular functions, enabling the subjective evaluation and integration of different opinions into the model. The purpose of our model is to support enterprise decision-making by taking into account sustainability aspects and the different expectations of interested parties. Our model helps identify intervention points and manages subjectivity in the field so that the decisions of enterprise managers better reflect the expectations and perspectives of those involved. The model we built is significantly different from previously used and developed indexes, as it functions as an enterprise-controlling model and index during sustainability evaluation. The developed model can also integrate company-specific and global sustainability indicators. Our research contributes to the development of sustainability evaluation methodology and the scientific examination of enterprise decision-making models. The controlling model we developed offers an integrated approach to managing the subjectivity of sustainability evaluation and the different expectations of stakeholder groups.