diff --git a/src/main/java/org/gcube/vremanagement/executor/api/SmartExecutor.java b/src/main/java/org/gcube/vremanagement/executor/api/SmartExecutor.java
index 5410c05..31dd62b 100644
--- a/src/main/java/org/gcube/vremanagement/executor/api/SmartExecutor.java
+++ b/src/main/java/org/gcube/vremanagement/executor/api/SmartExecutor.java
@@ -13,7 +13,6 @@ import org.gcube.vremanagement.executor.exception.LaunchException;
 import org.gcube.vremanagement.executor.exception.PluginInstanceNotFoundException;
 import org.gcube.vremanagement.executor.exception.PluginNotFoundException;
 import org.gcube.vremanagement.executor.plugin.PluginState;
-import org.quartz.SchedulerException;
 
 /**
  * Service Endpoint Interface
@@ -51,13 +50,15 @@ public interface SmartExecutor {
 	
 	/**
 	 * The method use the provided UUID as String to unschedule a previous 
-	 * scheduled task.
+	 * scheduled task and stop the current execution (if any).
 	 * @param executionIdentifier UUID as String which identify the execution
+	 * @return return true if the current execution correctly unscheduled and 
+	 * stopped. False otherwise.
 	 * @throws Exception if there is no execution identified by the provided 
 	 * UUID execution identifier as String
 	 */
 	@SOAPBinding(parameterStyle=ParameterStyle.WRAPPED)
-	public void unSchedule(String executionIdentifier) throws SchedulerException;
+	public boolean unSchedule(String executionIdentifier) throws Exception;
 	
 	
 	/**