Sometimes a step within a process chain seems to be ‘hanging’ for no particular reason, causing the process chain to wait in vain for it to finish.
I’ve added, as an example, a screen-shot of a ‘hanging’ process chain step which extracted 0 records from its source system, but did not continue to proceed with the next step:

To jump start this part of the process chain, open the monitor and display the IDoc information

When you select an IDoc within the Transfer section, the following information will be shown by the SAP BW system and at the bottom of the screen you can find the corresponding IDoc number:

As you might see (to the right of the selected IDoc number), the status of this IDoc is “64” which means the IDoc is ready to be transferred to the application.
Copy (or remember) this IDoc number, execute transaction code BD87, enter the IDoc number and press the execute button

The following status monitor screen will be shown in which you can process the IDoc by pressing the Process button

After having processed the ‘hanging’ IDoc, the IDoc status (if all went well) has been switched to status 53 which means the IDoc has been posted to the application successfully

The ‘hanging’ process chain will automatically be triggered by the status change of this IDoc and will come out of hibernation mode…