The application of Internet of Things (IoT) technologies makes it possible to improve the performance of technological and logistic processes. These processes can include a wide range of IoT technologies and solutions, like cloud, fog or edge computing, intelligent tools and gentelligent products, mobile robots, 3D printing, virtual reality or last but not at least digital twin solutions. Within the frame of this article the author describes the potential of digital twin technology to improve the performance of real-time optimisation in complex logistics systems. After a short literature review, this paper introduces the conception of digital twin solutions. The model of digital twin supported real-time optimisation of an in-plant logistics system is described including the structure, the mathematical model, the solution algorithm, and the computational results. The scenario analysis of the described system validates the model and the efficiency of digital twin solutions.