diff --git a/addons/product_expiry/models/production_lot.py b/addons/product_expiry/models/production_lot.py
index 5ddaf4a5f60..bb40157dc76 100644
--- a/addons/product_expiry/models/production_lot.py
+++ b/addons/product_expiry/models/production_lot.py
@@ -1,7 +1,7 @@
 # -*- coding: utf-8 -*-
 # Part of Odoo. See LICENSE file for full copyright and licensing details.
 import datetime
-from odoo import api, fields, models, _
+from odoo import api, fields, models, SUPERUSER_ID, _
 
 
 class StockProductionLot(models.Model):
@@ -81,7 +81,7 @@ class StockProductionLot(models.Model):
                 ('mail_activity_type_id','=', mail_activity_type)]))
         for lot in lots:
             lot.activity_schedule('product_expiry.mail_activity_type_alert_date_reached',
-            user_id=lot.product_id.responsible_id.id, note=_("The alert date has been reached for this lot/serial number")
+            user_id=lot.product_id.responsible_id.id or SUPERUSER_ID, note=_("The alert date has been reached for this lot/serial number")
         )
 
 class ProcurementGroup(models.Model):
diff --git a/addons/stock/data/stock_data.xml b/addons/stock/data/stock_data.xml
index be5f560d1a1..52ea5baf809 100644
--- a/addons/stock/data/stock_data.xml
+++ b/addons/stock/data/stock_data.xml
@@ -66,7 +66,7 @@
         
         <!-- set a lower sequence on the mto route than on the resupply routes -->
         <record id="route_warehouse0_mto" model='stock.location.route'>
-            <field name="name">Make To Order</field>
+            <field name="name">Replenish on Order (MTO)</field>
             <field name="company_id"></field>
             <field name="sequence">5</field>
         </record>
diff --git a/addons/stock/models/product.py b/addons/stock/models/product.py
index 2b3f9af2baa..2f16867a42c 100644
--- a/addons/stock/models/product.py
+++ b/addons/stock/models/product.py
@@ -402,7 +402,7 @@ class ProductTemplate(models.Model):
     _inherit = 'product.template'
 
     responsible_id = fields.Many2one(
-        'res.users', string='Responsible', default=lambda self: self.env.uid, required=True,
+        'res.users', string='Responsible',
         help="This user will be responsible of the next activities related to logistic operations for this product.")
     type = fields.Selection(selection_add=[('product', 'Storable Product')])
     property_stock_production = fields.Many2one(
@@ -443,7 +443,7 @@ class ProductTemplate(models.Model):
     route_ids = fields.Many2many(
         'stock.location.route', 'stock_route_product', 'product_id', 'route_id', 'Routes',
         domain=[('product_selectable', '=', True)],
-        help="Depending on the modules installed, this will allow you to define the route of the product: whether it will be bought, manufactured, MTO, etc.")
+        help="Depending on the modules installed, this will allow you to define the route of the product: whether it will be bought, manufactured, replenished on order, etc.")
     nbr_reordering_rules = fields.Integer('Reordering Rules', compute='_compute_nbr_reordering_rules')
     # TDE FIXME: really used ?
     reordering_min_qty = fields.Float(compute='_compute_nbr_reordering_rules')
diff --git a/addons/stock/models/stock_rule.py b/addons/stock/models/stock_rule.py
index 5dc9132834c..21fbf20125c 100644
--- a/addons/stock/models/stock_rule.py
+++ b/addons/stock/models/stock_rule.py
@@ -7,7 +7,7 @@ from dateutil.relativedelta import relativedelta
 from odoo.tools.misc import split_every
 from psycopg2 import OperationalError
 
-from odoo import api, fields, models, registry, _
+from odoo import api, fields, models, registry, SUPERUSER_ID, _
 from odoo.osv import expression
 from odoo.tools import DEFAULT_SERVER_DATETIME_FORMAT, float_compare, float_round
 
@@ -245,7 +245,7 @@ class StockRule(models.Model):
             self.env['mail.activity'].create({
                 'activity_type_id': activity_type_id,
                 'note': note,
-                'user_id': product_id.responsible_id.id,
+                'user_id': product_id.responsible_id.id or SUPERUSER_ID,
                 'res_id': product_id.product_tmpl_id.id,
                 'res_model_id': self.env.ref('product.model_product_template').id,
             })
diff --git a/odoo/addons/test_main_flows/static/src/js/tour.js b/odoo/addons/test_main_flows/static/src/js/tour.js
index d79036346b2..4d29ed4e608 100644
--- a/odoo/addons/test_main_flows/static/src/js/tour.js
+++ b/odoo/addons/test_main_flows/static/src/js/tour.js
@@ -58,8 +58,8 @@ tour.register('main_flow_tour', {
     content: _t('Uncheck Buy'),
     position: 'right',
 }, {
-    trigger: '.o_field_widget[name=route_ids] .custom-checkbox > label:contains("Make To Order")',
-    content: _t('Uncheck  Make To Order'),
+    trigger: '.o_field_widget[name=route_ids] .custom-checkbox > label:contains("Replenish on Order (MTO)")',
+    content: _t('Uncheck  Replenish on Order (MTO)'),
     position: 'right',
 }, {
     trigger: '.o_notebook a:contains("General Information")',
@@ -114,8 +114,8 @@ tour.register('main_flow_tour', {
     content: _t('Go to inventory tab'),
     position: 'top',
 }, {
-    trigger: '.o_field_widget[name=route_ids] .custom-checkbox > label:contains("Make To Order")',
-    content: _t('Check Make To Order'),
+    trigger: '.o_field_widget[name=route_ids] .custom-checkbox > label:contains("Replenish on Order (MTO)")',
+    content: _t('Check Replenish on Order (MTO)'),
     position: 'right',
 }, {
     trigger: '.o_notebook a:contains("Purchase")',