Performing a Find Disconnected trace task on a large geometric network takes a long time to complete, even when the result of the trace is a small number of features.
The Find Disconnected trace task returns all features in the geometric network that cannot be reached from the given input flags. In order to accomplish this, the trace task must look at all features in the geometric network.
Run the Find Disconnected trace task sparingly on large geometric networks.
You can use VB to create custom trace tasks that limit the extent of the network to be searched when finding disconnected network elements.