Accurate simulation provides a significant means for cost reduction during planning and operation of manufacturing installations. Within the projects Realistic Robot Simulation the standards Robot Controller Simulation (RCS) Interface and Virtual Robot Controller (VRC) Interface were defined by international consortia of leading car makers, robot and simulator manufacturers and line builders, with Fraunhofer IPK, Berlin as project manager. For enabling accurate simulation of complete manufacturing lines, a new project entitled Virtual Programmable Logic Controller (VPLC) is planned. The article outlines the resulting potential of cost reduction throughout the life-time of an installation and gives an overview on the application of the standards for cost reduction.