Adding and Removing Server Processes 
The installation procedure configures the optimal number of server processes in an instance based on the available hardware resources. This enables optimal utilization of the hardware resources and of the capacity of the ICM to handle multiple server processes. If you need to add more server processes to an existing Java instance, you can do that manually using the AS Java Config Tool.
You can configure the number of server processes on two levels:
template level
If you define the number of server processes on a template level, the number will be relevant for all Java instances in the cluster.
Java instance level
If you specify the number of server processes for a particular Java instance, the number will be relevant only for this particular Java instance.
Prerequisites
You have installed the basic components of the cluster.
Make sure the AS Java is stopped.
More information: Starting and Stopping Systems and Instances.
Procedure
Start the Config Tool by double-clicking the configtool script file in <SAP_install_dir>/<system_name>/<instance_name>/j2ee/configtool directory.
From the tree-structure, choose the relevant template or Java instance according to whether you want to apply the configuration on the entire cluster or on a particular Java instance only.
Choose the Servers tab.
In the Custom number of server nodes field, enter the number of server processes you want to have.
Choose Check Value to verify that your machine is capable of handling the number of server processes you entered. Correct the value if necessary.
NoteThis option is available at instance level only.
If the template configuration allows you to enter a formula instead of an exact value, then the Check Value option calculates the formula and displays the value.
End of the note.Choose Set.
If you want a node in a particular instance to be debuggable, check Enable Debug Node.
NoteYou can set only one node for debugging in an instance.
End of the note.Choose
(Apply Changes).Restart the cluster.