One contemporary form of quality assurance starts during the run-up to production already, with selective simulation calculations that cover the specified component properties, the production process employed and the resultant requirements on the material. In this connection an important aspect is the calculation of the mould filling process and the subsequent crosslink reaction, This is illustrated with a number of practical examples, The CADMOULD/ MEFIGUM and CADMOULD/MEX program systems developed at the IKV permit the rheological and thermal simulation of the filling and heating phase during the injection moulding of elastomer components, making allowance for the kinetics of crosslink.