Situation-aware information assistance strongly depends on the quality of available contextual background knowledge for an application domain and on its automatic processing. In this paper we present a conceptual approach towards using cognitive architectures to provide information assistance and allow complex decision making based on expert knowledge. We transfer our approach into a technical concept which was fi�nally implemented as part of the Plant@Hand assembly assistance system within a mobile workshop trolley. The paper gives insights into our work on formalizing knowledge and providing ad-hoc mechanisms for planning, assisting and controlling assembly tasks on the manufacturing shop floor.