Due to a rising number of variants and a decreasing number of sold items per unit indirect costs like development or recycling costs gain more im-portance. Existing cost estimation approaches do not deal with the challenges of high uncertainty in early phases of PD in an appropriate way. Therefore, a method to model, estimate and analyse different kinds of costs is presented. This method is based on existing process costing approaches and combines them with a statistical simulation to deal with uncertainties and the high level of complexity. The method can be used within target costing to define cost goals, continuous cost calculation during the process as well as documentation and controlling of estimated and actual costs.