An important aspect of modern vehicle design is an effective suppression of maintenance cost. To optimize the design of brakes for commercial vehicles and busses, DAF Trucks developed a calculation method which predicts operational life and wear rate of drum brake linings. The calculations are carried out by means of a time domain simulation using output data from the route simulation module of TOPEC, a computerised transport advice system. The computer program does not only provide good operational life estimators concerning the brake linings, but also predicts the behaviour of contact pressure distribution, temperature distribution and mechanical forces on vital construction parts during brake manoeuvres. This v; ay these important quantities can be optimized during the design stage of the brake assembly by calculating their numerical values for a wide range of brake design proposals.