diff --git a/src/aeros_simulation/router.py b/src/aeros_simulation/router.py
index fbdf124..145e8f2 100644
--- a/src/aeros_simulation/router.py
+++ b/src/aeros_simulation/router.py
@@ -236,6 +236,7 @@ async def calculate_contribution(
     try:
         contribution_results = defaultdict()
         simulations_eq = select(AerosEquipment)
+        eaf_contributions_data =  []
 
         eqs = (await db_session.execute(simulations_eq)).scalars().all()
         
@@ -300,10 +301,12 @@ async def calculate_contribution(
                 eaf_contribution=eaf_contribution
             )
             
-            db_session.add(eaf_conf)
-            await db_session.commit()
+            eaf_contributions_data.append(eaf_conf)
+            
             await db_session.delete(simulation)
 
+        db_session.add_all(eaf_contributions_data)
+        await db_session.commit()
         return {
             "data": contribution_results,
             "status": "success",