Resource Network 
The resource network is a business object in SAP APO that is defined by a positive list of allowed directed connections between two or more resources. A directed connection means that the connection from Resource 1 to Resource 2 is not the same as the inverse connection from Resource 2 to Resource 1.
Defining resource networks as separate business objects reduces the number of master data permutations in the PPM and PDS by eliminating the need for mode coupling. A resource network's data needs to be created and maintained in SAP APO, and can be modified at any time.
Prerequisites
You have created multiple resources.
Note
You can integrate the existing resource network of SAP ERP with SAP APO using the report RESNET_TRANSFER.
You use this object to model existing production constraints more precisely, with the objective of creating a finite and technically feasible production schedule. Resource networks simplify the modeling of resource restrictions for consecutive operations or orders.
To create a resource network, complete the steps below:
On the SAP Easy Access screen, choose
Advanced Planning and Optimization 
Master Data Resource Resource Network [folder] Resource
Network 
.On the selection screen, enter a resource network name in the Resource Network field.
Choose Create.
On the next screen, the Self-Reference checkbox is selected by default. Deselect it if you want to define the linkages of the resources to themselves individually.
On the General Data tab page, enter a description in the Network Description field.
Go to the Resource Links tab page and choose the Insert Link pushbutton.
Select or enter valid resources in the Resource From and Resource To fields.
Set a priority value in the Priority field.
Select a resource network and choose the Assign Model pushbutton.
Select a model in the new window.
Choose the Assign Objects to Model pushbutton (Shift+F1) and then the Continue pushbutton.
Save your entries.