diff --git a/addons/stock/models/stock_move.py b/addons/stock/models/stock_move.py
index f3d0ba9ffce..24fc4d79e5c 100644
--- a/addons/stock/models/stock_move.py
+++ b/addons/stock/models/stock_move.py
@@ -182,15 +182,14 @@ class StockMove(models.Model):
         if self.product_id:
             self.description_picking = self.product_id._get_description(self.picking_type_id)
 
-    @api.depends('has_tracking', 'picking_type_id.use_create_lots', 'picking_type_id.use_existing_lots', 'picking_type_id.show_reserved', 'picking_type_id.show_operations')
+    @api.depends('has_tracking', 'picking_type_id.use_create_lots', 'picking_type_id.use_existing_lots', 'state')
     def _compute_display_assign_serial(self):
         for move in self:
             move.display_assign_serial = (
                 move.has_tracking == 'serial' and
                 move.state in ('partially_available', 'assigned', 'confirmed') and
                 move.picking_type_id.use_create_lots and
-                not move.picking_type_id.use_existing_lots and
-                not move.picking_type_id.show_reserved
+                not move.picking_type_id.use_existing_lots
             )
 
     @api.depends('picking_id.is_locked')
@@ -641,23 +640,14 @@ class StockMove(models.Model):
         suffix = splitted[1]
         initial_number = int(initial_number)
 
-        move_lines_commands = []
-        location_dest = self.location_dest_id._get_putaway_strategy(self.product_id) or self.location_dest_id
+        lot_names = []
         for i in range(0, next_serial_count):
-            lot_name = '%s%s%s' % (
+            lot_names.append('%s%s%s' % (
                 prefix,
                 str(initial_number + i).zfill(padding),
                 suffix
-            )
-            move_lines_commands.append((0, 0, {
-                'lot_name': lot_name,
-                'qty_done': 1,
-                'product_id': self.product_id.id,
-                'product_uom_id': self.product_id.uom_id.id,
-                'location_id': self.location_id.id,
-                'location_dest_id': location_dest.id,
-                'picking_id': self.picking_id.id,
-            }))
+            ))
+        move_lines_commands = self._generate_serial_move_line_commands(lot_names)
         self.write({'move_line_ids': move_lines_commands})
         return True
 
@@ -816,31 +806,34 @@ class StockMove(models.Model):
         self.name = product.partner_ref
         self.product_uom = product.uom_id.id
 
-    @api.onchange('move_line_nosuggest_ids')
-    def onchange_move_line_nosuggest_ids(self):
+    @api.onchange('move_line_ids', 'move_line_nosuggest_ids')
+    def onchange_move_line_ids(self):
+        if not self.picking_type_id.use_create_lots:
+            # This onchange manages the creation of multiple lot name. We don't
+            # need that if the picking type disallows the creation of new lots.
+            return
+
         breaking_char = '\n'
-        move_lines_to_create = []
-        for move_line in self.move_line_nosuggest_ids:
+        if self.picking_type_id.show_reserved:
+            move_lines = self.move_line_ids
+        else:
+            move_lines = self.move_line_nosuggest_ids
+
+        for move_line in move_lines:
             # Look if the `lot_name` contains multiple values.
             if breaking_char in (move_line.lot_name or ''):
-                splitted_lines = move_line.lot_name.split(breaking_char)
-                splitted_lines = list(filter(lambda line: line, splitted_lines))
-                move_line.lot_name = splitted_lines[0]
-                # For each SN line, set move ine data...
-                for line in splitted_lines[1:]:
-                    move_line_data = {
-                        'lot_name': line,
-                        'qty_done': 1,
-                        'product_id': move_line.product_id.id,
-                        'product_uom_id': move_line.product_id.uom_id.id,
-                        'location_id': move_line.location_id.id,
-                        'location_dest_id': move_line.location_dest_id.id,
-                        'owner_id': move_line.owner_id or False,
-                        'package_id': move_line.package_id or False,
-                    }
-                    move_lines_to_create += [(0, 0, move_line_data)]
-                # ... then create these move lines.
-                self.update({'move_line_nosuggest_ids': move_lines_to_create})
+                split_lines = move_line.lot_name.split(breaking_char)
+                split_lines = list(filter(None, split_lines))
+                move_line.lot_name = split_lines[0]
+                move_lines_commands = self._generate_serial_move_line_commands(
+                    split_lines[1:],
+                    origin_move_line=move_line,
+                )
+                if self.picking_type_id.show_reserved:
+                    self.update({'move_line_ids': move_lines_commands})
+                else:
+                    self.update({'move_line_nosuggest_ids': move_lines_commands})
+                break
 
     @api.onchange('product_uom')
     def onchange_product_uom(self):
@@ -904,6 +897,64 @@ class StockMove(models.Model):
     def _assign_picking_post_process(self, new=False):
         pass
 
+    def _generate_serial_move_line_commands(self, lot_names, origin_move_line=None):
+        """Return a list of commands to update the move lines (write on
+        existing ones or create new ones).
+        Called when user want to create and assign multiple serial numbers in
+        one time (using the button/wizard or copy-paste a list in the field).
+
+        :param lot_names: A list containing all serial number to assign.
+        :type lot_names: list
+        :param origin_move_line: A move line to duplicate the value from, default to None
+        :type origin_move_line: record of :class:`stock.move.line`
+        :return: A list of commands to create/update :class:`stock.move.line`
+        :rtype: list
+        """
+        self.ensure_one()
+
+        # Select the right move lines depending of the picking type configuration.
+        move_lines = self.env['stock.move.line']
+        if self.picking_type_id.show_reserved:
+            move_lines = self.move_line_ids.filtered(lambda ml: not ml.lot_id and not ml.lot_name)
+        else:
+            move_lines = self.move_line_nosuggest_ids.filtered(lambda ml: not ml.lot_id and not ml.lot_name)
+
+        if origin_move_line:
+            location_dest = origin_move_line.location_dest_id
+        else:
+            location_dest = self.location_dest_id._get_putaway_strategy(self.product_id)
+        move_line_vals = {
+            'location_dest_id': location_dest.id or self.location_dest_id.id,
+            'location_id': self.location_id.id,
+            'product_id': self.product_id.id,
+            'product_uom_id': self.product_id.uom_id.id,
+            'qty_done': 1,
+        }
+        if origin_move_line:
+            # `owner_id` and `package_id` are taken only in the case we create
+            # new move lines from an existing move line. Also, updates the
+            # `qty_done` because it could be usefull for products tracked by lot.
+            move_line_vals.update({
+                'owner_id': origin_move_line.owner_id.id,
+                'package_id': origin_move_line.package_id.id,
+                'qty_done': origin_move_line.qty_done or 1,
+            })
+
+        move_lines_commands = []
+        for lot_name in lot_names:
+            # We write the lot name on an existing move line (if we have still one)...
+            if move_lines:
+                move_lines_commands.append((1, move_lines[0].id, {
+                    'lot_name': lot_name,
+                    'qty_done': 1,
+                }))
+                move_lines = move_lines[1:]
+            # ... or create a new move line with the serial name.
+            else:
+                move_line_cmd = dict(move_line_vals, lot_name=lot_name)
+                move_lines_commands.append((0, 0, move_line_cmd))
+        return move_lines_commands
+
     def _get_new_picking_values(self):
         """ return create values for new picking that will be linked with group
         of moves in self.
diff --git a/addons/stock/tests/test_generate_serial_numbers.py b/addons/stock/tests/test_generate_serial_numbers.py
index ab534983696..1c3e79454f1 100644
--- a/addons/stock/tests/test_generate_serial_numbers.py
+++ b/addons/stock/tests/test_generate_serial_numbers.py
@@ -17,7 +17,7 @@ class StockGenerate(SavepointCase):
         })
         cls.uom_unit = cls.env.ref('uom.product_uom_unit')
 
-        warehouse = cls.env['stock.warehouse'].create({
+        cls.warehouse = cls.env['stock.warehouse'].create({
             'name': 'Base Warehouse',
             'reception_steps': 'one_step',
             'delivery_steps': 'ship_only',
@@ -25,11 +25,11 @@ class StockGenerate(SavepointCase):
         })
         cls.location = cls.env['stock.location'].create({
             'name': 'Room A',
-            'location_id': warehouse.lot_stock_id.id,
+            'location_id': cls.warehouse.lot_stock_id.id,
         })
         cls.location_dest = cls.env['stock.location'].create({
             'name': 'Room B',
-            'location_id': warehouse.lot_stock_id.id,
+            'location_id': cls.warehouse.lot_stock_id.id,
         })
 
         cls.Wizard = cls.env['stock.assign.serial']
@@ -275,7 +275,12 @@ class StockGenerate(SavepointCase):
         has five new move lines with the right `lot_name`.
         """
         nbre_of_lines = 10
+        picking_type = self.env['stock.picking.type'].search([
+            ('use_create_lots', '=', True),
+            ('warehouse_id', '=', self.warehouse.id)
+        ])
         move = self.get_new_move(nbre_of_lines)
+        move.picking_type_id = picking_type
         # We must begin with a move with 10 move lines.
         self.assertEqual(len(move.move_line_ids), nbre_of_lines)
 
@@ -307,7 +312,12 @@ class StockGenerate(SavepointCase):
         been correctly set.
         """
         nbre_of_lines = 5
+        picking_type = self.env['stock.picking.type'].search([
+            ('use_create_lots', '=', True),
+            ('warehouse_id', '=', self.warehouse.id)
+        ])
         move = self.get_new_move(nbre_of_lines)
+        move.picking_type_id = picking_type
         # We must begin with a move with five move lines.
         self.assertEqual(len(move.move_line_ids), nbre_of_lines)
 
diff --git a/addons/stock/views/stock_move_views.xml b/addons/stock/views/stock_move_views.xml
index 97bb1e2d8fe..4aa69439b00 100644
--- a/addons/stock/views/stock_move_views.xml
+++ b/addons/stock/views/stock_move_views.xml
@@ -228,7 +228,7 @@
             <field name="inherit_id" ref="stock.view_stock_move_operations"/>
             <field name="arch" type="xml">
                 <field name="move_line_ids" position="replace">
-                    <field name="move_line_nosuggest_ids" attrs="{'readonly': [('state', 'in', ('done', 'cancel'))]}" context="{'tree_view_ref': 'stock.view_stock_move_line_operation_tree_lot_name_as_textarea','default_picking_id': picking_id, 'default_move_id': id, 'default_product_id': product_id, 'default_location_id': location_id, 'default_location_dest_id': location_dest_id, 'default_company_id': company_id}"/>
+                    <field name="move_line_nosuggest_ids" attrs="{'readonly': [('state', 'in', ('done', 'cancel'))]}" context="{'tree_view_ref': 'stock.view_stock_move_line_operation_tree','default_picking_id': picking_id, 'default_move_id': id, 'default_product_id': product_id, 'default_location_id': location_id, 'default_location_dest_id': location_dest_id, 'default_company_id': company_id}"/>
                 </field>
             </field>
         </record>
@@ -257,7 +257,10 @@
                             'default_product_id': parent.product_id,
                         }"
                     />
-                    <field name="lot_name" attrs="{'readonly': ['&amp;', ('package_level_id', '!=', False), ('parent.picking_type_entire_packs', '=', True)]}" invisible="not context.get('show_lots_text')" groups="stock.group_production_lot"/>
+                    <field name="lot_name" widget="text" groups="stock.group_production_lot"
+                        placeholder="Write your SN/LN one by one or copy paste a list."
+                        attrs="{'readonly': ['&amp;', ('package_level_id', '!=', False), ('parent.picking_type_entire_packs', '=', True)]}"
+                        invisible="not context.get('show_lots_text')"/>
                     <field name="package_id" attrs="{'readonly': ['&amp;', ('package_level_id', '!=', False), ('parent.picking_type_entire_packs', '=', True)]}" invisible="not context.get('show_package')" groups="stock.group_tracking_lot"/>
                     <field name="result_package_id" attrs="{'readonly': ['&amp;', ('package_level_id', '!=', False), ('parent.picking_type_entire_packs', '=', True)]}" groups="stock.group_tracking_lot"/>
                     <field name="owner_id" attrs="{'readonly': ['&amp;', ('package_level_id', '!=', False), ('parent.picking_type_entire_packs', '=', True)]}" invisible="not context.get('show_owner')" groups="stock.group_tracking_owner"/>
@@ -300,20 +303,6 @@
             </field>
         </record>
 
-        <record id="view_stock_move_line_operation_tree_lot_name_as_textarea" model="ir.ui.view">
-            <field name="name">stock.move.line.operations.tree</field>
-            <field name="model">stock.move.line</field>
-            <field name="priority">1000</field>
-            <field name="mode">primary</field>
-            <field name="inherit_id" ref="stock.view_stock_move_line_operation_tree"/>
-            <field name="arch" type="xml">
-                <field name="lot_name" position="attributes">
-                    <attribute name="widget">text</attribute>
-                    <attribute name="placeholder">Write your SN/LN one by one or copy paste a list.</attribute>
-                </field>
-            </field>
-        </record>
-
         <record id="view_move_form" model="ir.ui.view">
             <field name="name">stock.move.form</field>
             <field name="model">stock.move</field>