Context. Modeling and simulating software behavior using Palladio can be an important step in ensuring the softwares quality. Problem. However, the end results of a simulation may not be sufficient to understand where and why a self-adaptive system decided to reconfigure itself. Objective. This thesis extends the Palladio tool chain, adding a component that can generate the explanations to these and more questions based on the Slingshot simulator. Method. For this, we gathered usage scenarios where adaptation decisions required further explanations. Using them as requirements, we implemented our explanation generation component as an expert system with a focus on flexibility and expandability. Result. The component functions as a modular extension to Palladios Slingshot simulator that can be dynamically configured to give explanations in different forms as required. For our evaluation we performed a user survey on the importance of different questions to be answered. Conclusion. We believe that the component we have implemented is flexible enough to serve as an easily expanded and adapted tool for explanation generation as well as similar tasks. The scenarios we created as well as the ideas behind them may help others define similar requirements in a more structured way.