Due to more Internet accessibility and mobile penetration, the shopping trend has changed from brick-and-mortar store to online shopping. This caused a huge surge in Thailand e-business to satisfy such variability in demand. With large capital requirement for e-business retailers especially in operation and marketing areas, many of them fail to materialize sufficient profits after have been operating for a certain years, putting themselves into difficult cash flow situations. Therefore, cost-saving opportunities need to be identified, providing them with the right strategies and executions for a better chance of survival. The study of Thailand's top e-retailer had been carried out to critically evaluating its supply chain practices and operational performance in order to develop the most appropriate strategies that aid in establishing operational model for cost reduction in e-business. The focused areas are procurement, supply base management, internal collaboration, inventory management, and forecasting approach. Such research findings and the constructed operational model can be helpful to e-business managers seeking cost reduction and rooms for improvement in supply chain area.