In the background of flat world and widely international collaborations, it becomes critical for supply chain members to collaborate with each other. In this paper, we try to quantify the value of collaboration by improving business processes from the simulation point of view. We discuss different kinds of business process improvement manners, create simulation scenarios with or without collaboration, and analyze the simulation results. With the power of business process simulation, we have the capability to evaluate the benefits of collaboration with consideration of the details of operations and stochastic characters. © 2011 IEEE.