This research would be more developed in several directions considering some other realistic supply chains, like analyzing bullwhip effect in multi-retailer, multi-supplier and multi-product supply chains. We assume that each product was ordered independently; it could be supposed that two products ordering system follows joint replenishment policies. In addition, other demand models like vector ARMA are to be considered as market demand pattern. Other forecasting methods like MSSE and time series model for lead-time demand prediction can be considered as future research. In addition, cost sensitive supply chains can be considered in the next works