diff --git a/SAS/TMSS/src/tmss/tmssapp/models/scheduling.py b/SAS/TMSS/src/tmss/tmssapp/models/scheduling.py
index 38f26a66ab3160d2d16a438bd125e639bd0c5b0a..af6094a67bdb2f7fcbbb1b77d8fe9bb21d0cb8f0 100644
--- a/SAS/TMSS/src/tmss/tmssapp/models/scheduling.py
+++ b/SAS/TMSS/src/tmss/tmssapp/models/scheduling.py
@@ -225,6 +225,10 @@ class Subtask(BasicCommon):
         '''
         return Dataproduct.objects.filter(producer__subtask_id=self.id)
 
+    def get_transformed_input_dataproduct(self, output_dataproduct_id: int) -> 'Dataproduct':
+        '''return the transformed input dataproduct for the given output_dataproduct_id.'''
+        return self.input_dataproducts.get(consumers__output_id=output_dataproduct_id)
+
     def get_transformed_output_dataproduct(self, input_dataproduct_id: int) -> 'Dataproduct':
         '''return the transformed output dataproduct for the given input_dataproduct_id.'''
         return self.output_dataproducts.get(producers__input_id=input_dataproduct_id)