Scheduling involves allocation of plant resources to comply with orders as well as constraints, and thus it defines which run-mode to use and when to perform changeovers. This study will focus on the formulation of scheduling problem for crude oil unloading at the front end of a refinery. This problem involves crude oil vessels, storage tanks, charge tanks and crude distillation units. Among the benefits of having a good schedule include having optimized crude storage, ensuring safe refinery operations and may help maintain profit margins. Refinery scheduling is often a complex problem, but its successful implementation with the help of suitable mathematical models can result in significant cost savings. © 2011 IEEE.