A facility cannot be smoothly operated if not properly maintained. Hence, facility operations and maintenance (O&M) function has obtained a noteworthy recognition due to its significant contribution made for the continuous operation of a facility, core-business performance and occupant’s satisfaction. However, the diverse nature of facility O&M functions necessitates effective supply chains. In particular, the crucial elements engaged in O&M functions such as the parties involved, information flows, finance flows and service/product flows have been neglected in previous studies. Hence, this study aims to develop a model for supply chain management of facility O&M function in apparel sector. Given the importance of apparel manufacturing to Sri Lankan national economy, the study was focused on apparel factories. An in-depth literature review followed by case study design under qualitative approach was deployed for empirical investigation. The collected data was analyzed manual content analysis. According to the case study findings, supply chain management in O&M functions have been done in ad-hoc manner. The study developed a SCM process for facility O&M functions incorporating three O&M sub processes; i.e. (a) customer relationship management, (b) internal supply chain management, and (c) supplier relationship management. The research findings can be used as a guide by the facility O&M teams for optimising the performance of O&M supply chain functions.