The growing complexity of manufacturing calls for new approaches to support the human workforce with situation-aware information and tools which in consequence ease the process of understanding and applying work related knowledge. With this paper we introduce a theoretical model for a systematic information transfer between assistance system and worker. It defines assistance objectives and reviews the role of artifacts during the assistance process focusing on the cognitive aspects of work. Our approach was implemented using smartwatches for application in industrial assembly environments extending the Plant@Hand manufacturing performance support system.