In this study, an OEM assembling a single product using multiple-components is considered. The components are obtained either by manufacturing from raw materials and or remanufacturing from returns and or procuring from external suppliers. The returns, product returned after use by the customer, are obtained after paying a return acquisition price. The return acquisition price is a fixed price paid based on the utilisation time of the return. The returns are dismantled into components: 1) which can be remanufactured; 2) which cannot be remanufactured (meant for disposal). The manufacturing, remanufacturing and assembly operations are integrated as a closed loop supply chain system and can be performed by any OEM. It appears from the literature review that the OEM-CLSC system, where components are remanufactured by OEM themselves, has not been considered in any of the previous research literature. This study addresses this research gap by considering a singleproduct multi-component remanufacturing of an OEM-CLSC problem. For addressing the research problem considered, a mathematical model is proposed to identify the optimal inventories and the production plan. Finally, an empirical analysis is carried out to determine the breakeven capacity for remanufacturing operation by suitably introducing a breakeven analysis model.