The tundish, working as a buffer and distributor of liquid steel between ladle and continuous casting (CC) molds, plays a key role in affecting the performance of the CC machine, steel quality, and plant productivity. The successful tundish design is critical due to the demand of superheat control, improvement of steel cleanliness and reduction in material cost during continuous casting. A design of experiment analysis (DOE) was employed to explore the possibilities and analyse two-dimensional heat transfer through refractory linings of a single-strand tundish, with the consideration of the thickness and the thermal conductivity of the lining materials. In addition, a three-dimensional conjugate heat transfer (CHT) model was applied in the tundish, taking into account the molten steel flow and heat conduction in the linings. The detailed CFD simulation of the flow field with Simcenter STAR-CCM+ allows to compare different design variants. Both, steady-state and transient flow fields and temperature distributions were calculated with consideration of the heat losses in the tundish as well as to identify dead zone areas. Transient simulations employing a passive scalar methodology were used to calculate the residence time distribution (RTD), measured by the E-curve and F-curves. As a key intermediate device, the tundish is repeatedly used during the continuous casting process. The tundish refractory is directly influenced by the thermal cycling of the high temperature molten steel in the vessel. The larger thermal stress can lead to a shorter life of tundish and serious production accidents. Therefore, the service life problem of the tundish has always been a particular focus of attention. In this study, the research on the temperature distribution and thermal stress field for the tundish has also been conducted based on an integrated fluid-thermal-structural analysis. A special focus of this study was to demonstrate the analysis methodology of combining a DOE analysis and CFD modelling capabilities of the Siemens Xcelerator portfolio that allows to explore the lining design in terms of thickness and thermal conductivity for the given process conditions during tundish operations. The thermal states of the tundish have a significant impact on the energy usage required for heating the tundish, while the overall thickness of lining has a significant impact on production and operating costs. The digital thread outlined in this work helps to model the complexity and to create a more favourable tundish design. This reduces the energy usage, the carbon footprint, and the resulting costs of the steel production process.