The production ramp-up process is critical to stay competitive and to capture market share but there are some common problems encountered during ramp-up. Among others one problem is related to the maturity of the production processes, including unforeseen bottlenecks. This paper contributes to the production planning part of the ramp-up process by showing how to predict the process time for new parts that is to be introduced in an existing manufacturing environment. A statistical model based on historical product-data is applied and the potential advantages of the model are outlined.