diff --git a/addons/mrp/i18n/mrp.pot b/addons/mrp/i18n/mrp.pot
index 65f030aaf2c..2a49830b260 100644
--- a/addons/mrp/i18n/mrp.pot
+++ b/addons/mrp/i18n/mrp.pot
@@ -6676,15 +6676,6 @@ msgid ""
 "                        </b>"
 msgstr ""
 
-#. module: mrp
-#. odoo-python
-#: code:addons/mrp/wizard/change_production_qty.py:0
-#, python-format
-msgid ""
-"You have already processed %(quantity)s. Please input a quantity higher than"
-" %(quantity)s "
-msgstr ""
-
 #. module: mrp
 #: model_terms:ir.ui.view,arch_db:mrp.view_assign_serial_numbers_production
 msgid ""
diff --git a/addons/mrp/tests/test_order.py b/addons/mrp/tests/test_order.py
index babec6424cb..e054032eba0 100644
--- a/addons/mrp/tests/test_order.py
+++ b/addons/mrp/tests/test_order.py
@@ -304,18 +304,26 @@ class TestMrpOrder(TestMrpCommon):
         mo_form.qty_producing = 2
         mo = mo_form.save()
 
+        # Produce & backorder
+        action = mo.button_mark_done()
+        backorder = Form(self.env['mrp.production.backorder'].with_context(**action['context']))
+        backorder.save().action_backorder()
+        mo_backorder = mo.procurement_group_id.mrp_production_ids[-1]
+        self.assertEqual(mo_backorder.product_qty, 1)
+
         update_quantity_wizard = self.env['change.production.qty'].create({
-            'mo_id': mo.id,
-            'product_qty': 5,
+            'mo_id': mo_backorder.id,
+            'product_qty': 3,
         })
         update_quantity_wizard.change_prod_qty()
-        mo_form = Form(mo)
-        mo_form.qty_producing = 5
-        mo = mo_form.save()
-        mo.button_mark_done()
+        mo_back_form = Form(mo_backorder)
+        mo_back_form.qty_producing = 3
+        mo_backorder = mo_back_form.save()
+        mo_backorder.button_mark_done()
 
-        self.assertEqual(sum(mo.move_raw_ids.filtered(lambda m: m.product_id == p1).mapped('quantity')), 20)
-        self.assertEqual(sum(mo.move_finished_ids.mapped('quantity')), 5)
+        productions = mo | mo_backorder
+        self.assertEqual(sum(productions.move_raw_ids.filtered(lambda m: m.product_id == p1).mapped('quantity')), 20)
+        self.assertEqual(sum(productions.move_finished_ids.mapped('quantity')), 5)
 
     def test_update_quantity_3(self):
         bom = self.env['mrp.bom'].create({
diff --git a/addons/mrp/wizard/change_production_qty.py b/addons/mrp/wizard/change_production_qty.py
index 018193347f8..6782676406e 100644
--- a/addons/mrp/wizard/change_production_qty.py
+++ b/addons/mrp/wizard/change_production_qty.py
@@ -3,7 +3,7 @@
 
 from odoo import api, fields, models, _
 from odoo.exceptions import UserError
-from odoo.tools import float_is_zero, float_round
+from odoo.tools import float_is_zero
 
 
 class ChangeProductionQty(models.TransientModel):
@@ -58,16 +58,10 @@ class ChangeProductionQty(models.TransientModel):
         precision = self.env['decimal.precision'].precision_get('Product Unit of Measure')
         for wizard in self:
             production = wizard.mo_id
-            if wizard.product_qty < production.qty_produced:
-                format_qty = '%.{precision}f'.format(precision=precision)
-                raise UserError(_(
-                    "You have already processed %(quantity)s. Please input a quantity higher than %(quantity)s ",
-                    quantity=format_qty % production.qty_produced,
-                ))
             old_production_qty = production.product_qty
             new_production_qty = wizard.product_qty
 
-            factor = (new_production_qty - production.qty_produced) / (old_production_qty - production.qty_produced)
+            factor = new_production_qty / old_production_qty
             update_info = production._update_raw_moves(factor)
             documents = {}
             for move, old_qty, new_qty in update_info:
@@ -80,8 +74,12 @@ class ChangeProductionQty(models.TransientModel):
                         else:
                             documents[key] = [value]
             production._log_manufacture_exception(documents)
-            self._update_finished_moves(production, new_production_qty - production.qty_produced, old_production_qty - production.qty_produced)
+            self._update_finished_moves(production, new_production_qty, old_production_qty)
             production.write({'product_qty': new_production_qty})
+            if not float_is_zero(production.qty_producing, precision_rounding=production.product_uom_id.rounding) and\
+               not production.workorder_ids:
+                production.qty_producing = new_production_qty
+                production._set_qty_producing()
 
             for wo in production.workorder_ids:
                 operation = wo.operation_id