This paper provides three aggregation algorithms for deriving system nets from sets of partially-ordered causal runs. The three algorithms differ with respect to the assumptions about the information contained in the causal runs. Specifically, we look at the situations where labels of conditions (i.e. references to places) or events (i.e. references to transitions) are unknown. Since the paper focuses on aggregation in the context of process mining, we solely look at workflow nets, i.e. a class of Petri nets with unique start and end places. The difference of the work presented here and most work on process mining is the assumption that events are logged as partial orders instead of linear traces. Although the work is inspired by applicatio...