Page History

...

try{
    Map person = dispatcher.runSync("createPracticePerson", createPersonCtx);
 }catch (GenericServiceException e){
     Debug.logError(e.toString(), module);          
     return "error";
 }
return "success";

...

Don't forget to restart the server after doing this entry.
Now run the service through form and check the records in PartyRole entity. You will find a role is set for the party created because synchrounously you have triggered a service by eeca rule for setting up the role for the party created.
The main difference here is that you are triggering a service when an operation is performed on the entity. In our case it is "create".
Note :  Here you have created a saparate menu to understand the concept separately. As you written seca for the service "createPracticePerson", so where ever in your practice application you will be calling this service that seca will trigger "createPartyRoleVisitor" and on the other hand when a party will be created "createPartyRoleCustomer" will be triggered.
Output Screen :

 

 Group Group Service:

    Group services are used to call more then one services as a group. Service groups are a set of services which should run when calling the initial service. You define a service using the group service engine, and include all the parameters/attributes needed for all the services in the group. The location attribute is not needed for groupservices, the invoke attribute defines the name of the group to run. When this service is invoked the group is called and the services defined in the group are called as defined.
For mor details on this visit :  http://docs.ofbiz.org/display/OFBTECH/Service+Engine+Guide
For the implementation of Group service follow these steps: 
Step - 1 : Add another menu item to applicatoin menu bar by name "Group Service".(Do the needful entries for target in controller.xml)
Step - 2 : Now create new screen and a form for creation of the person because the target for the form will be the group service which we will be defining.
Note : Now the time is to define the group service. We will be defining the group service for the services which we have implemented for this practice application.
Step - 3 : You will be defining the service group in services.xml file.(Take reference from services.xml of party component).
Just write one more service which will be setting the role "CLIENT" for the party which will be created by createPracticePerson Service. 
 Create a group service by name "partyGroup" like :

...