We present a modeling system for simulation of dial-a-ride services. It can be used as a tool for understanding and study how different designs, and different ways to operate a dial-a-ride service, affect the performance and efficiency of the service. The system simulates the operation of a dynamic dial-a-ride service that operates with multiple fleets of vehicles with different capacities, schedules and depots. It can be used to investigate how the setting of service and cost parameters and the design of the service affect the total cost for the operator and level of service for the customer. We describe the different modules in the system and the possible uses of the system. A short simulation study is performed to exemplify how it can be used. In this study the effects of including costs for customer discomfort are evaluated.