Settings for Routing Selection 
You can make the following settings for routing selection:
You can use the Routing selection key to specify:
You assign the routing selection key to an order type in Customizing for Shop Floor Control, by choosing Master data
The selection priorities specify the priorities according to which the automatic routing selection should take place (task list type, usage, status).
You maintain the possible selection priorities in Customizing for Shop Floor Control, by choosing Operations
With automatic routing selection you can specify in the material master that the automatic selection is to take place using the production version maintained in the material master instead of with the selection priorities. To achieve this, specify a value in the Alternative selection field in the MRP section that defines the bill of material selection using the production version.
To maintain the material master choose Logistics
If you work without a routing default values are used for operation data. The system creates an operation with these default values.
To maintain the possible default values in Customizing for Shop Floor Control, choose Operations
® Routing selection ® Define default values.