diff --git a/src/aeros_simulation/schema.py b/src/aeros_simulation/schema.py
index 7b3ecec..9b06fce 100644
--- a/src/aeros_simulation/schema.py
+++ b/src/aeros_simulation/schema.py
@@ -27,6 +27,7 @@ class SimulationInput(DefultBase):
     OverhaulDuration:  Optional[int] = Field(1200)
     AhmJobId: Optional[str] = Field(None, max_length=50)
     deratings: Optional[List[dict]] = []
+    maintenance_outages: Optional[List[dict]] = []
 
 class SimulationNode(DefultBase):
     id: UUID
diff --git a/src/aeros_simulation/simulation_save_service.py b/src/aeros_simulation/simulation_save_service.py
index 18b9c66..0d44cc1 100644
--- a/src/aeros_simulation/simulation_save_service.py
+++ b/src/aeros_simulation/simulation_save_service.py
@@ -252,7 +252,7 @@ async def create_calc_result_object(
 
 
 async def calculate_plant_eaf(
-    db_session: DbSession, simulation_id: UUID, mo_downtime: int, po_downtime:int, oh_interval:int, offset:int, manual_deratings: list = None
+    db_session: DbSession, simulation_id: UUID, po_downtime:int, oh_interval:int, offset:int, manual_deratings: list = None, manual_mo: list = None
 ):
     """Calculate overall plant EAF from individual node results."""
     plant_calc_data = await get_plant_calc_result(
@@ -268,17 +268,33 @@ async def calculate_plant_eaf(
     ) > oh_interval
     
     
+    # Calculate manual MO hours (full outage) and MD hours (derating)
+    manual_mo_outage_hours = 0.0
+    manual_mo_equiv_hours = 0.0
+    max_capacity = 630
+    
+    if manual_mo:
+        for mo in manual_mo:
+            h = float(mo.get('hours', 0))
+            c = float(mo.get('capacity', 0))
+            if c <= 0:
+                manual_mo_outage_hours += h
+            else:
+                derating = max_capacity - c
+                if derating > 0:
+                    manual_mo_equiv_hours += (h * derating / max_capacity)
+    
     # Calculate outages
     if is_oh_from_aeros:
-        seasonal_outage = (mo_downtime) * 24 + po_downtime
-        forced_outage = max(0, plant_calc_data.total_downtime - (po_downtime))
+        seasonal_outage = manual_mo_outage_hours + po_downtime
+        forced_outage = max(0, plant_calc_data.total_downtime - po_downtime)
     else:
-        seasonal_outage = mo_downtime * 24
+        seasonal_outage = manual_mo_outage_hours
         forced_outage = max(0, plant_calc_data.total_downtime)
     
         
     # Adjust uptime
-    total_uptime = max(0, plant_calc_data.total_uptime - (mo_downtime * 24))
+    total_uptime = max(0, plant_calc_data.total_uptime - manual_mo_outage_hours)
     
     # Total period time
     total_period_time = total_uptime + seasonal_outage + forced_outage
@@ -293,9 +309,15 @@ async def calculate_plant_eaf(
         manual_deratings=manual_deratings
     )
 
-    
-    
-    plant_calc_data.total_mo_downtime = mo_downtime
+    # # Adjust EAF and edh for manual MO deratings
+    # if manual_mo_equiv_hours > 0:
+    #     # eaf remains reduced by both edh and manual_mo_equiv_hours
+    #     eaf = ((total_uptime - (edh + manual_mo_equiv_hours)) / total_period_time) * 100
+    #     # maintenance deratings should contribute to scheduled metrics (SOF/ESOF)
+    #     sof = ((seasonal_outage + manual_mo_equiv_hours) / total_period_time) * 100
+    #     edh += manual_mo_equiv_hours
+
+    plant_calc_data.total_mo_downtime = manual_mo_outage_hours
     plant_calc_data.total_po_downtime = po_downtime
     plant_calc_data.eaf = eaf
     plant_calc_data.efor = efor
diff --git a/temporal/activity.py b/temporal/activity.py
index c11c6f4..842f26b 100644
--- a/temporal/activity.py
+++ b/temporal/activity.py
@@ -62,11 +62,11 @@ async def calculate_plant_eaf_activity(params: dict):
         return await calculate_plant_eaf(
             db_session=db_session,
             simulation_id=params["HubCnnId"],
-            mo_downtime=params["MaintenanceOutages"],
             po_downtime=params["OverhaulDuration"],
             oh_interval=params["OverhaulInterval"],
             offset=params["OffSet"],
-            manual_deratings=params.get("deratings", [])
+            manual_deratings=params.get("deratings", []),
+            manual_mo=params.get("maintenance_outages", [])
         )