This paper describes an approach towards situation-based annotation management on the basis of work integrated activity recognition and situation detection. We motivate situation-based annotations as a means for collecting and processing contextual knowledge on the work domain in order to improve the quality of information assistance at mobile assembly workplaces. Especially, when we make use of automated processes which aim to detect the worker's ongoing activities and situations, we have to deal at the same time with errors and wrongly inferred assumptions on reality. Here we see the strengths of annotation management which can be used to revise contextual background knowledge, required for determining the autonomous behavior, in case of errors and deviations between inferred and real situations.