diff --git a/product/ERP5Legacy/tests/testLegacySimulationPackingList.py b/product/ERP5Legacy/tests/testLegacySimulationPackingList.py
index 8d7a026ab95d8bf2fa60a9cd90bf6a6ec1bef2a3..c2f70e0a168d2198565c3aa453a4fa6f3e02cfcd 100644
--- a/product/ERP5Legacy/tests/testLegacySimulationPackingList.py
+++ b/product/ERP5Legacy/tests/testLegacySimulationPackingList.py
@@ -567,6 +567,7 @@ class TestPackingListMixin(TestOrderMixin):
       simulation_movement.getDeliveryValue().edit(quantity=self.default_quantity-1)
       simulation_movement.expand()
 
+
   def stepModifySimulationLineStopDate(self,sequence=None, sequence_list=None, **kw):
     """
     Modify simulation line stop date
@@ -579,6 +580,18 @@ class TestPackingListMixin(TestOrderMixin):
       simulation_movement.edit(stop_date=self.datetime+15)
       simulation_movement.expand()
 
+  def stepModifySimulationLineStartDate(self,sequence=None, sequence_list=None, **kw):
+    """
+    Modify simulation line start date
+    """
+    applied_rule = sequence.get('applied_rule')
+    simulation_movement_list = applied_rule.objectValues()
+    resource_list = sequence.get('resource_list')
+    for simulation_movement in simulation_movement_list:
+      simulation_movement.recordProperty('start_date')
+      simulation_movement.edit(stop_date=self.datetime+15)
+      simulation_movement.expand()
+
   def stepModifyOneSimulationLineStartDate(self,sequence=None, sequence_list=None, **kw):
     """
       Check if simulation movement are disconnected