This paper shows how automatic optimization of scheduling problems has been integrated within the automation framework of a semiconductor factory. Special attention is paid to the requirements arising from such an application in real world production in terms of constraints and objectives as well as from a factory integration perspective such as autonomous operation, high availability and efficient maintenance. Subsequently, possible solutions on how such requirements can be addressed will be discussed. Thereby, the advantage of using Constraint Programming solvers is highlighted. Knowledge that was gained during the implementation is presented for selected cases followed by the benefits that were achieved.