The advent of e-commerce has prompted many manufacturers to redesign their traditional channel structure by engaging in direct sales. In this paper. we present a dual channel inventory model based on queuing theory in a manufacturer-retailer supply chain. consisting of a traditional retail channel and a direct channel which stocks are kept in both upper and lower echelon. https://www.markbroyard.com/special-offer-g-fuel-spider-verse-glitch-mix-black-strawberry-guava-flavour-zero-sugar-energy-drink-16fl-oz-for-sale-super-save/