diff --git a/addons/mrp/models/mrp_production.py b/addons/mrp/models/mrp_production.py
index 70250d72e63..18055c8481d 100644
--- a/addons/mrp/models/mrp_production.py
+++ b/addons/mrp/models/mrp_production.py
@@ -575,7 +575,6 @@ class MrpProduction(models.Model):
             'product_uom': product_uom,
             'operation_id': operation_id,
             'byproduct_id': byproduct_id,
-            'unit_factor': product_uom_qty / self.product_qty,
             'name': self.name,
             'date': self.date_planned_start,
             'date_expected': self.date_planned_finished,
@@ -671,7 +670,6 @@ class MrpProduction(models.Model):
                 move[0].with_context(do_not_unreserve=True).write({'product_uom_qty': quantity})
                 move[0]._recompute_state()
                 move[0]._action_assign()
-                move[0].unit_factor = remaining_qty and (quantity - move[0].quantity_done) / remaining_qty or 1.0
                 return move[0], old_qty, quantity
             else:
                 if move[0].quantity_done > 0:
@@ -759,7 +757,6 @@ class MrpProduction(models.Model):
             for move_raw in production.move_raw_ids:
                 move_raw.write({
                     'group_id': production.procurement_group_id.id,
-                    'unit_factor': move_raw.product_uom_qty / production.product_qty,
                     'reference': production.name,  # set reference when MO name is different than 'New'
                 })
             production._generate_finished_moves()
diff --git a/addons/mrp/models/stock_move.py b/addons/mrp/models/stock_move.py
index d09c3980fe3..499135b2d4a 100644
--- a/addons/mrp/models/stock_move.py
+++ b/addons/mrp/models/stock_move.py
@@ -87,7 +87,7 @@ class StockMove(models.Model):
     byproduct_id = fields.Many2one(
         'mrp.bom.byproduct', 'By-products', check_company=True,
         help="By-product line that generated the move in a manufacturing order")
-    unit_factor = fields.Float('Unit Factor', default=1)
+    unit_factor = fields.Float('Unit Factor', compute='_compute_unit_factor', store=True)
     is_done = fields.Boolean(
         'Done', compute='_compute_is_done',
         store=True,
@@ -135,6 +135,15 @@ class StockMove(models.Model):
         for move in self:
             move.is_done = (move.state in ('done', 'cancel'))
 
+    @api.depends('product_uom_qty')
+    def _compute_unit_factor(self):
+        for move in self:
+            mo = move.raw_material_production_id or move.production_id
+            if mo:
+                move.unit_factor = (move.product_uom_qty - move.quantity_done) / ((mo.product_qty - mo.qty_produced) or 1)
+            else:
+                move.unit_factor = 1.0
+
     @api.model
     def default_get(self, fields_list):
         defaults = super(StockMove, self).default_get(fields_list)