Inventory redistribution and emergency replenishment in supply chains have long been studied in various contexts. From a strategic perspective, lateral transshipments can be beneficial for a variety of general supply chains to cope with the mismatch between periodic realized demands and inventory levels. Similarly, the emergency replenishment from supply sources has also been used as a tool to mitigate the demand uncertainty. In this paper, we consider the integration of instantaneous transshipments and emergency shipments in a multi-location inventory system consisting of a distribution center, and multiple retailers. A mathematical optimization model is formulated first, and then an approach based on a Stochastic Genetic Algorithm (SGA) is presented to solve the model. The objective of the model is to determine optimal replenishment policies for the multi-location inventory system. A coarse-to-fine procedure is employed to reduce the computational time. Finally, computational results are given to show the validity of the presented approach.