Efficient and reliable optical design requires knowledge of the production chain, the materials used, and the environmental circumstances in the field of operation. This is realized in the comprehensive modelling approach consisting of three steps: • Design for manufacturing, i.e. the model must be adjusted to the process chain. Knowledge of design rules is required. • Robust design, i.e. optimization of the functional design with the objective of a compensation of the tolerance influences on the system’s performance. Knowledge of the tolerances of the individual process steps is required. • Reliable design with respect to environmental and operational effects, respectively. Coupling of an optical and mechanical simulation tool is required to form the optical simulation environment. The availability of process knowledge such as e.g. design rules and manufacturing tolerances is ensured by coupling of the optical simulation environment with a process knowledge database. Integration of measured surface data in this simulation environment enables a realistic simulation and analysis of real, manufactured optics. This approach allows e.g. for the evaluation of replication methods such as precision molding or injection molding against high-precision manufacturing methods, e.g. diamond turning.