This paper describes an object-orientated simulation approach towards an integrated planning of production systems. The main obstacle for an integrated use of simulation over different planning areas and stages are the different views on a production system. Therefore, an object model is developed, which enables the co-existence of different views and levels of detail in the same simulation model while maintaining its consistency. This is achieved by combining object-orientated technology with a network based simulation approach. The prevailing idea is to offer the opportunity to re-use existing models for the investigation of different aspects of a production system. The is abstractly described as a conceptual object model and is thus, independent from a concrete simulation language, tool or environment. The last part of this paper introduces the simulation tool OSim, that implements this object model and demonstrates its usage through an example. 1 RESERVATIONS ON APPLYING SIMULATIO...