General purpose simulators offer an easy way to create simulations for a large variety of scenarios, although they are prepackaged with some drawbacks. To achieve their usefulness for most cases they need additional overhead and custom made extensions for special behavior which comes at enormous runtime and development cost. Especially when working with simulation-based scheduling, these are severe issues since runtime is precious and automated generation of the models is a necessity. Another approach to simulation challenges is the creation of a very specific custom-built simulator which focuses on a chosen domain where it excels compared to other simulators. In our paper, we introduce a simulator designed specifically for the simulation of complex assembly lines with their common characteristics including thousands of activities, realistic schedules, priority rules, resources and model restrictions. It furthermore allows the creation of new strategies for different aspects of scheduling in this environment.