Creating a Subnetwork 
The network to whose activity you want to add detail using subnetworks should already exist. You must have defined the subnetwork parameters in Project System customizing.
Choose .
Enter the required subnetwork date in the initial screen for the network.
Choose
( )
.
The network header for the subnetwork appears.
Choose the Organization tab page.
In the Subnetwork field, specify the numbers of the superior network and the appropriate activity from it.
This is the activity to which you want to add detail using the subnetwork you are now creating.
( )
The activity in the superior network must not have status Closed or Technically complete .
Enter the other data in the network header.
Complete the data for the subnetwork - for example, with activities, components, and so on.
Save your data.
If detail has been added to an activity by means of a subnetwork, the Subnetwork exists indicator in the detail screen for the activity is active.
To switch between the superior network and the subnetwork, choose Superior network in the network header of the relevant network.