This contribution describes an assembly planning methodology in a concurrent engineering environment and a supporting computer system featuring continuous data management and standardized data exchange. The assembly planning is related to results available from the product’s designer and suitable computer tools provide support for each task. There are 5 major groups of input information that is needed for the various tasks of assembly planning. Data created during planning are stored in an object-oriented database to avoid conversion and can even be re-used directly for start-up or production. Therefore the communication between the computer tools themselves and between the tools and the real automated devices has been standardized according to MMS and implemented as CORBA-objects. An equally important system characteristic is represented by the analyses based on the planning status; they can be applied throughout the planning process. Increasingly detailed and realistic analyses are thus possible during the whole planning process.