Manufacturing companies must prioritize resource efficiency to remain competitive in the face of increasing demand for goods. Linear economic models, such as the ‘Take-Make-Dispose’ paradigm, are no longer adequate for meeting the demands of modern society, ecology, and regulation. The circular economy offers a resource-efficient alternative. In the circular economy, Re-Assembly is a promising strategy within this framework, involving industrial reprocessing of serial products to extend their lifecycle. However, the absence of optimized product designs for reprocessing hinders widespread adoption and economic viability of Re-Assembly processes. Therefore, integrated development across product design, production, and Re-Assembly is crucial to address this challenge. To achieve economic viability, it is necessary to evaluate costs throughout the product lifecycle. To enable companies to make informed decisions regarding the Re-Assembly process, a continuous cost assessment supported by sophisticated cost models is necessary. This paper presents a comprehensive cost model tailored to assess the economic feasibility of industrial Re-Assembly processes. The relevant cost drivers and necessary resources for the reprocessing are identified and used as input for the subsequently developed process-oriented cost model. This cost model is transferred into an optimization model. The model aims to enhance the sustainability and profitability of circular economy practices.