In today’s competitive environment every foundry industries requires minimum rejection of component; rejection is caused by undesired uncertainty found in component’s it can be shrinkage cavity, sand inclusion, cold shuts etc. Reduce defect probability we need better setup and proper process control parameters without shop floor trials. Therefore industries develops many software packages for simulation of casting process it shows the virtual view like mould filling, solidification, cooling meanwhile it also predict the location, shape and volume of defects. Now a days simulation becomes the powerful tool to understand the casting phenomenon it enables the production of reliable, economical, with high accuracy cast components this paper describe comprehensive literature review about benefits of casting simulation and how to reduce defect like shrinkage cavity and feeder optimization is described.