Nowadays, to stay competitive businesses must be able to quickly adapt to rapidly changing marketing environment and/or exploit new market opportunities. Simulation of business process allows to analyze various business scenarios under different circumstances, provides an understanding of the most important factors affecting the process, and helps in identifying critical parts of the process. However, traditional business process simulation approaches consider business process as a pre-defined sequence of activities, limiting possibilities to adapt a process model to changes occurring in the business environment. In this paper we present a goal-oriented approach to simulate dynamic business processes, where a complete set of process activities as well as their execution sequence are not known in advance. The paper highlights main principles of the dynamic business process simulation approach, presents a prototype tool implementing the approach, and provides an example, demonstrating the dynamic business process simulation.