The economic performance of companies in developed countries is currently being tested by the global economic situation due to the Covid pandemic as well as the tense geopolitical context. Industry 4.0 concepts clearly contribute to increasing this overall performance for large companies. But their exploitation in the context of small businesses still remains confidential for SMEs. This article proposes to use sustainability combined with Industry 4.0 concepts such as advanced robotics, artificial intelligence and digital twins, designated by the European Commission as Industry 5.0, to solve this problem and encourage SMEs to use these concepts to improve their overall performance. This article therefore proposes the use of the digital twin as a tool for improving company performance by providing them with an intelligent real-time decision support system. This article is organized as follows: after a literature review on artificial intelligence, digital twins, and performance optimization, the sustainable methodology for digital transformation of companies will be presented. The architecture of the digital twin, as a decision support tool developed in this context, will be detailed. Finally, an example illustration will validate the concepts presented above and show their relevance in improving performance.