This study examines the operational performance of retail supply chain management by developing a continuous review model with inter-store transhipment. This study is seeking to improve the replenishment process and reduce total inventory costs by modelling the inter-store transhipment of multi-items at two store-level retailers. We are highlighting the importance of these models in cost control, customer service, and financial performance as well. The inter-store transhipment model developing in this study focus on near-optimal solutions for the retailer to synchronize a real-time consumer demand with inventory systems, while considering transportation costs, holding cost and shortage as key parameters. This model is designed with Monte Carlo simulation with fitted demand distributions uses the derived from the historical data from the one of real retailer in Thailand.