The assembly plays a key role in ensuring the competitiveness of industrial enterprises. From a logistics perspective, one of the central challenges with assembly processes is simultaneously and punctually supplying the necessary parts at the date required. In doing so, the goal is to satisfy the customers' desire for short throughput times and high schedule reliability, thus keeping inventory related costs as low as possible. The article presents a model which enables to evaluate the influence of the supply processes on the in due time supply situation of converging material flows.