CAx:
A multitude of computer aided systems such as CAD, CAE, CAM, CAP and CAQ are used for the planning stages right up to the quality control of a product. A CAD-system is a software module in the entire product life cycle which basically supports construction tasks. An improvement in the efficiency of the product life cycles can only be achieved by a continuity of data and processes. For this reason the compatibility of CAD-systems and other application programs plays a decisive role.

ERP - Enterprise Ressource Planning:
Completely integrated software solutions for manufacturing, finance, logistics, personell, projects, sales et al. They consist of a row of modular and preferably easy to implement components and so they provide functionality for all areas in a company.

CAx and ERP are integrated in a PLM-system, as they are both fundamental components of the product life cycle.