diff --git a/jsprit-core/src/main/java/jsprit/core/problem/solution/route/state/StateFactory.java b/jsprit-core/src/main/java/jsprit/core/problem/solution/route/state/StateFactory.java
index 803f18a1..e0cdadb4 100644
--- a/jsprit-core/src/main/java/jsprit/core/problem/solution/route/state/StateFactory.java
+++ b/jsprit-core/src/main/java/jsprit/core/problem/solution/route/state/StateFactory.java
@@ -45,15 +45,15 @@ public class StateFactory {
 	
 	public final static StateId DURATION = new StateIdImpl("duration", 5);
 	
-	public final static StateId LATEST_OPERATION_START_TIME = new StateIdImpl("latest_ost", 6);
+	public final static StateId LATEST_OPERATION_START_TIME = new StateIdImpl("latest_operation_start_time", 6);
 	
-	public final static StateId EARLIEST_OPERATION_START_TIME = new StateIdImpl("earliest_ost", 7);
+	public final static StateId EARLIEST_OPERATION_START_TIME = new StateIdImpl("earliest_operation_start_time", 7);
 	
 	public final static StateId FUTURE_MAXLOAD = new StateIdImpl("future_max_load", 8);
 	
 	public final static StateId PAST_MAXLOAD = new StateIdImpl("past_max_load", 9);
 	
-	final static List<String> reservedIds = Arrays.asList("max_load","load","costs","load_at_beginning","load_at_end","duration","latest_ost","earliest_ost"
+	final static List<String> reservedIds = Arrays.asList("max_load","load","costs","load_at_beginning","load_at_end","duration","latest_operation_start_time","earliest_operation_start_time"
 			,"future_max_load","past_max_load");