Manual Steps can be used to define any non-transportable activities that need to be done before or after a particular Transport is imported.
Manual Steps are maintained via the [Manual Steps] tab on the Transport Form, in the SAP GUI, Windows GUI or Web UI.
Most critically, it is possible to define whether the Manual Step should be done before/after the import of a transport (via the Run Manual Step dropdown), and whether it should hold up the import of subsequent transports (via the Allow Progress When Incomplete checkbox). It is also possible to define who will perform the Manual Step via the [Users] tab, and also define in which systems in the landscape path the Manual Step needs to be performed in the [Systems] tab.
Figure: Manual Step tab in the SAP GUI
Figure: Manual Step tab in the Web UI
Figure: Manual Step tab in the Windows GUI