Prevent auto display/assignment of next callable object

Question

Hi everybody,
I have the following scenario for a GP process:
fist step: maintain data
second step: approve data
The callable objects are WD4J.
I need to route the workflow to a role/group of users. It may happen, that the processor of step 1 is also a member of the role, that is responsible for step 2. Because of SOX compliance, he is not allowed to approve his own data. But if GP identifies the current user as the processor of the next callable object, the callable object is displayed directly and assigned to the user.
This results to the following question:
1) How can I avoid, that the callable object is called directly and force the users to go always to the uwl first, even if several following steps are assigned to the same user
2) How can I prevent that a user is not able to take a task if he was the predecessor of the first step, evenif he belogs to the role that is responsible for the task
I would like to avoid a workaround based on custom code.
Any hints are welcome.
Best regards,
René

Answer 1

Hi Fahad,
I tried same as you said but its not worked.
public void execute( com.sap.caf.eu.gp.co.api.IGPExecutionContext executionContext )
    this.executionContext=executionContext;
public void Complete( )
IUser usr =UMFactory.getUserFactory().getUserByLogonID("logonid");
          IGPProcessRoleInstance role = executionContext.getProcessRoleInstance() ;
          role.addRuntimeDefinedUser(usr) ;
I changedthe roleInitiator of next action is runtime defined.
but its not worked.
Regards,
Naga