Technologies are described for creating activity object instances corresponding to collection object instances, and for conducting tests between activity object instances and collection objects instances, and within a set of activity object instances. Tests can include determining whether collection object instances have counterpart activity object instances, and evaluating a collection object instance with respect to a corresponding activity object instance. Activity object instances can be set to be performed in a sequence, and a test can determine whether the sequence is consistent with sequencing rules. When activity object instances are automatically created from collection object instances, a user can be presented with a graphical user interface that includes representations of activity object instances, and the user can manipulate the graphical user interface to provide precedence information.