Just move up this line:
ksession.getWorkItemManager().registerWorkItemHandler("WebServicesCall", new SearchBookHandler());
Something like this:
//Register Work Item Handlers:
ksession.getWorkItemManager().registerWorkItemHandler("validation", new SimpleWorkhandler());
ksession.getWorkItemManager().registerWorkItemHandler("WebServicesCall", new SearchBookHandler());
//Start first instance
Map<String,Object> params = new HashMap<String,Object>();
params.put("userName", "jay4smile@yahoo.com");
params.put("password", "jay123");
ksession.startProcess("com.sample.bpmn",params);
//start second instance
ksession.startProcess("com.sample.bpmn");
Best Regards,