diff --git a/addons/hr/tests/common.py b/addons/hr/tests/common.py
index 4aacc2650e5..3211d758fea 100644
--- a/addons/hr/tests/common.py
+++ b/addons/hr/tests/common.py
@@ -7,7 +7,8 @@ from odoo.tests import common
 
 class TestHrCommon(common.TransactionCase):
 
-    def setUp(self):
-        super(TestHrCommon, self).setUp()
+    @classmethod
+    def setUpClass(cls):
+        super(TestHrCommon, cls).setUpClass()
 
-        self.res_users_hr_officer = mail_new_test_user(self.env, login='hro', groups='base.group_user,hr.group_hr_user', name='HR Officer', email='hro@example.com')
+        cls.res_users_hr_officer = mail_new_test_user(cls.env, login='hro', groups='base.group_user,hr.group_hr_user', name='HR Officer', email='hro@example.com')
diff --git a/addons/hr/tests/test_channel.py b/addons/hr/tests/test_channel.py
index 1b671ccd509..8caba47505f 100644
--- a/addons/hr/tests/test_channel.py
+++ b/addons/hr/tests/test_channel.py
@@ -6,15 +6,16 @@ from odoo.addons.hr.tests.common import TestHrCommon
 
 class TestChannel(TestHrCommon):
 
-    def setUp(self):
-        super(TestChannel, self).setUp()
+    @classmethod
+    def setUpClass(cls):
+        super(TestChannel, cls).setUpClass()
 
-        self.channel = self.env['mail.channel'].create({'name': 'Test'})
+        cls.channel = cls.env['mail.channel'].create({'name': 'Test'})
 
-        emp0 = self.env['hr.employee'].create({
-            'user_id': self.res_users_hr_officer.id,
+        emp0 = cls.env['hr.employee'].create({
+            'user_id': cls.res_users_hr_officer.id,
         })
-        self.department = self.env['hr.department'].create({
+        cls.department = cls.env['hr.department'].create({
             'name': 'Test Department',
             'member_ids': [(4, emp0.id)],
         })
diff --git a/addons/hr/tests/test_hr_flow.py b/addons/hr/tests/test_hr_flow.py
index 7442be48cc4..22edd44f11a 100644
--- a/addons/hr/tests/test_hr_flow.py
+++ b/addons/hr/tests/test_hr_flow.py
@@ -6,21 +6,22 @@ from odoo.addons.hr.tests.common import TestHrCommon
 
 class TestHrFlow(TestHrCommon):
 
-    def setUp(self):
-        super(TestHrFlow, self).setUp()
-        self.dep_rd = self.env['hr.department'].create({
+    @classmethod
+    def setUpClass(cls):
+        super(TestHrFlow, cls).setUpClass()
+        cls.dep_rd = cls.env['hr.department'].create({
             'name': 'Research & Development',
         })
-        self.job_developer = self.env['hr.job'].create({
+        cls.job_developer = cls.env['hr.job'].create({
             'name': 'Experienced Developer',
-            'department_id': self.dep_rd.id,
+            'department_id': cls.dep_rd.id,
             'no_of_recruitment': 5,
         })
-        self.employee_niv = self.env['hr.employee'].create({
+        cls.employee_niv = cls.env['hr.employee'].create({
             'name': 'Sharlene Rhodes',
         })
-        self.job_developer = self.job_developer.with_user(self.res_users_hr_officer.id)
-        self.employee_niv = self.employee_niv.with_user(self.res_users_hr_officer.id)
+        cls.job_developer = cls.job_developer.with_user(cls.res_users_hr_officer.id)
+        cls.employee_niv = cls.employee_niv.with_user(cls.res_users_hr_officer.id)
 
     def test_open2recruit2close_job(self):
 
diff --git a/addons/hr/tests/test_multi_company.py b/addons/hr/tests/test_multi_company.py
index 9fe6e99183f..2cbbf33482c 100644
--- a/addons/hr/tests/test_multi_company.py
+++ b/addons/hr/tests/test_multi_company.py
@@ -8,23 +8,24 @@ from odoo.addons.base.models.qweb import QWebException
 
 class TestMultiCompany(TestHrCommon):
 
-    def setUp(self):
-        super().setUp()
-        self.company_1 = self.env['res.company'].create({'name': 'Opoo'})
-        self.company_2 = self.env['res.company'].create({'name': 'Otoo'})
-        self.employees = self.env['hr.employee'].create([
-            {'name': 'Bidule', 'company_id': self.company_1.id},
-            {'name': 'Machin', 'company_id': self.company_2.id},
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.company_1 = cls.env['res.company'].create({'name': 'Opoo'})
+        cls.company_2 = cls.env['res.company'].create({'name': 'Otoo'})
+        cls.employees = cls.env['hr.employee'].create([
+            {'name': 'Bidule', 'company_id': cls.company_1.id},
+            {'name': 'Machin', 'company_id': cls.company_2.id},
         ])
-        self.res_users_hr_officer.company_ids = [
-            (4, self.company_1.id),
-            (4, self.company_2.id),
+        cls.res_users_hr_officer.company_ids = [
+            (4, cls.company_1.id),
+            (4, cls.company_2.id),
         ]
-        self.res_users_hr_officer.company_id = self.company_1.id
+        cls.res_users_hr_officer.company_id = cls.company_1.id
         # flush and invalidate the cache, otherwise a full cache may prevent
         # access rights to be checked
-        self.employees.flush()
-        self.employees.invalidate_cache()
+        cls.employees.flush()
+        cls.employees.invalidate_cache()
 
     def test_multi_company_report(self):
         content, content_type = self.env.ref('hr.hr_employee_print_badge').with_user(self.res_users_hr_officer).with_context(
diff --git a/addons/hr/tests/test_self_user_access.py b/addons/hr/tests/test_self_user_access.py
index 37aa30e00b1..6458deac69e 100644
--- a/addons/hr/tests/test_self_user_access.py
+++ b/addons/hr/tests/test_self_user_access.py
@@ -78,28 +78,29 @@ class TestSelfAccessProfile(TestHrCommon):
 
 class TestSelfAccessRights(TestHrCommon):
 
-    def setUp(self):
-        super(TestSelfAccessRights, self).setUp()
-        self.richard = new_test_user(self.env, login='ric', groups='base.group_user', name='Simple employee', email='ric@example.com')
-        self.richard_emp = self.env['hr.employee'].create({
+    @classmethod
+    def setUpClass(cls):
+        super(TestSelfAccessRights, cls).setUpClass()
+        cls.richard = new_test_user(cls.env, login='ric', groups='base.group_user', name='Simple employee', email='ric@example.com')
+        cls.richard_emp = cls.env['hr.employee'].create({
             'name': 'Richard',
-            'user_id': self.richard.id,
-            'address_home_id': self.env['res.partner'].create({'name': 'Richard', 'phone': '21454', 'type': 'private'}).id,
+            'user_id': cls.richard.id,
+            'address_home_id': cls.env['res.partner'].create({'name': 'Richard', 'phone': '21454', 'type': 'private'}).id,
         })
-        self.hubert = new_test_user(self.env, login='hub', groups='base.group_user', name='Simple employee', email='hub@example.com')
-        self.hubert_emp = self.env['hr.employee'].create({
+        cls.hubert = new_test_user(cls.env, login='hub', groups='base.group_user', name='Simple employee', email='hub@example.com')
+        cls.hubert_emp = cls.env['hr.employee'].create({
             'name': 'Hubert',
-            'user_id': self.hubert.id,
-            'address_home_id': self.env['res.partner'].create({'name': 'Hubert', 'type': 'private'}).id,
+            'user_id': cls.hubert.id,
+            'address_home_id': cls.env['res.partner'].create({'name': 'Hubert', 'type': 'private'}).id,
         })
 
-        self.protected_fields_emp = OrderedDict([(k, v) for k, v in self.env['hr.employee']._fields.items() if v.groups == 'hr.group_hr_user'])
+        cls.protected_fields_emp = OrderedDict([(k, v) for k, v in cls.env['hr.employee']._fields.items() if v.groups == 'hr.group_hr_user'])
         # Compute fields and id field are always readable by everyone
-        self.read_protected_fields_emp = OrderedDict([(k, v) for k, v in self.env['hr.employee']._fields.items() if not v.compute and k != 'id'])
-        self.self_protected_fields_user = OrderedDict([
+        cls.read_protected_fields_emp = OrderedDict([(k, v) for k, v in cls.env['hr.employee']._fields.items() if not v.compute and k != 'id'])
+        cls.self_protected_fields_user = OrderedDict([
             (k, v)
-            for k, v in self.env['res.users']._fields.items()
-            if v.groups == 'hr.group_hr_user' and k in self.env['res.users'].SELF_READABLE_FIELDS
+            for k, v in cls.env['res.users']._fields.items()
+            if v.groups == 'hr.group_hr_user' and k in cls.env['res.users'].SELF_READABLE_FIELDS
         ])
 
     # Read hr.employee #
diff --git a/addons/hr_attendance/tests/test_hr_attendance_constraints.py b/addons/hr_attendance/tests/test_hr_attendance_constraints.py
index 15f585f6732..8184f9c5d39 100644
--- a/addons/hr_attendance/tests/test_hr_attendance_constraints.py
+++ b/addons/hr_attendance/tests/test_hr_attendance_constraints.py
@@ -2,19 +2,21 @@
 
 import time
 
-from odoo.tests.common import TransactionCase
+from odoo.tests.common import tagged, TransactionCase
 
 
+@tagged('jesaispas')
 class TestHrAttendance(TransactionCase):
     """Tests for attendance date ranges validity"""
 
-    def setUp(self):
-        super(TestHrAttendance, self).setUp()
-        self.attendance = self.env['hr.attendance']
-        self.test_employee = self.env['hr.employee'].create({'name': "Jacky"})
-        # demo data contains set up for self.test_employee
-        self.open_attendance = self.attendance.create({
-            'employee_id': self.test_employee.id,
+    @classmethod
+    def setUpClass(cls):
+        super(TestHrAttendance, cls).setUpClass()
+        cls.attendance = cls.env['hr.attendance']
+        cls.test_employee = cls.env['hr.employee'].create({'name': "Jacky"})
+        # demo data contains set up for cls.test_employee
+        cls.open_attendance = cls.attendance.create({
+            'employee_id': cls.test_employee.id,
             'check_in': time.strftime('%Y-%m-10 10:00'),
         })
 
diff --git a/addons/hr_attendance/tests/test_hr_attendance_process.py b/addons/hr_attendance/tests/test_hr_attendance_process.py
index 0a7a2db6155..098cf07737b 100644
--- a/addons/hr_attendance/tests/test_hr_attendance_process.py
+++ b/addons/hr_attendance/tests/test_hr_attendance_process.py
@@ -6,26 +6,33 @@ from unittest.mock import patch
 
 from odoo import fields
 from odoo.tests import new_test_user
-from odoo.tests.common import TransactionCase
+from odoo.tests.common import tagged, TransactionCase
 
 
+@tagged('attendance_process')
 class TestHrAttendance(TransactionCase):
     """Test for presence validity"""
 
-    def setUp(self):
-        super(TestHrAttendance, self).setUp()
-        self.user = new_test_user(self.env, login='fru', groups='base.group_user,hr_attendance.group_hr_attendance_use_pin')
-        self.user_no_pin = new_test_user(self.env, login='gru', groups='base.group_user')
-        self.test_employee = self.env['hr.employee'].create({
+    @classmethod
+    def setUpClass(cls):
+        super(TestHrAttendance, cls).setUpClass()
+        cls.user = new_test_user(cls.env, login='fru', groups='base.group_user,hr_attendance.group_hr_attendance_use_pin')
+        cls.user_no_pin = new_test_user(cls.env, login='gru', groups='base.group_user')
+        cls.test_employee = cls.env['hr.employee'].create({
             'name': "François Russie",
-            'user_id': self.user.id,
+            'user_id': cls.user.id,
             'pin': '1234',
         })
-        self.employee_kiosk = self.env['hr.employee'].create({
+        cls.employee_kiosk = cls.env['hr.employee'].create({
             'name': "Machiavel",
             'pin': '5678',
         })
 
+    def setUp(self):
+        super().setUp()
+        # Cache error if not done during setup
+        (self.test_employee | self.employee_kiosk).last_attendance_id.unlink()
+
     def test_employee_state(self):
         # Make sure the attendance of the employee will display correctly
         assert self.test_employee.attendance_state == 'checked_out'
diff --git a/addons/hr_holidays/tests/common.py b/addons/hr_holidays/tests/common.py
index 83e0df4d673..72497b1b6a4 100644
--- a/addons/hr_holidays/tests/common.py
+++ b/addons/hr_holidays/tests/common.py
@@ -7,50 +7,51 @@ from odoo.tests import common
 
 class TestHrHolidaysCommon(common.TransactionCase):
 
-    def setUp(self):
-        super(TestHrHolidaysCommon, self).setUp()
-        self.env.user.tz = 'Europe/Brussels'
+    @classmethod
+    def setUpClass(cls):
+        super(TestHrHolidaysCommon, cls).setUpClass()
+        cls.env.user.tz = 'Europe/Brussels'
 
         # Test users to use through the various tests
-        self.user_hruser = mail_new_test_user(self.env, login='armande', groups='base.group_user,hr_holidays.group_hr_holidays_user')
-        self.user_hruser_id = self.user_hruser.id
+        cls.user_hruser = mail_new_test_user(cls.env, login='armande', groups='base.group_user,hr_holidays.group_hr_holidays_user')
+        cls.user_hruser_id = cls.user_hruser.id
 
-        self.user_hrmanager = mail_new_test_user(self.env, login='bastien', groups='base.group_user,hr_holidays.group_hr_holidays_manager')
-        self.user_hrmanager_id = self.user_hrmanager.id
+        cls.user_hrmanager = mail_new_test_user(cls.env, login='bastien', groups='base.group_user,hr_holidays.group_hr_holidays_manager')
+        cls.user_hrmanager_id = cls.user_hrmanager.id
 
-        self.user_employee = mail_new_test_user(self.env, login='david', groups='base.group_user')
-        self.user_employee_id = self.user_employee.id
+        cls.user_employee = mail_new_test_user(cls.env, login='david', groups='base.group_user')
+        cls.user_employee_id = cls.user_employee.id
 
         # Hr Data
-        Department = self.env['hr.department'].with_context(tracking_disable=True)
+        Department = cls.env['hr.department'].with_context(tracking_disable=True)
 
-        self.hr_dept = Department.create({
+        cls.hr_dept = Department.create({
             'name': 'Human Resources',
         })
-        self.rd_dept = Department.create({
+        cls.rd_dept = Department.create({
             'name': 'Research and devlopment',
         })
 
-        self.employee_emp = self.env['hr.employee'].create({
+        cls.employee_emp = cls.env['hr.employee'].create({
             'name': 'David Employee',
-            'user_id': self.user_employee_id,
-            'department_id': self.rd_dept.id,
+            'user_id': cls.user_employee_id,
+            'department_id': cls.rd_dept.id,
         })
-        self.employee_emp_id = self.employee_emp.id
+        cls.employee_emp_id = cls.employee_emp.id
 
-        self.employee_hruser = self.env['hr.employee'].create({
+        cls.employee_hruser = cls.env['hr.employee'].create({
             'name': 'Armande HrUser',
-            'user_id': self.user_hruser_id,
-            'department_id': self.rd_dept.id,
+            'user_id': cls.user_hruser_id,
+            'department_id': cls.rd_dept.id,
         })
-        self.employee_hruser_id = self.employee_hruser.id
+        cls.employee_hruser_id = cls.employee_hruser.id
 
-        self.employee_hrmanager = self.env['hr.employee'].create({
+        cls.employee_hrmanager = cls.env['hr.employee'].create({
             'name': 'Bastien HrManager',
-            'user_id': self.user_hrmanager_id,
-            'department_id': self.hr_dept.id,
-            'parent_id': self.employee_hruser_id,
+            'user_id': cls.user_hrmanager_id,
+            'department_id': cls.hr_dept.id,
+            'parent_id': cls.employee_hruser_id,
         })
-        self.employee_hrmanager_id = self.employee_hrmanager.id
+        cls.employee_hrmanager_id = cls.employee_hrmanager.id
 
-        self.rd_dept.write({'manager_id': self.employee_hruser_id})
+        cls.rd_dept.write({'manager_id': cls.employee_hruser_id})
diff --git a/addons/hr_holidays/tests/test_access_rights.py b/addons/hr_holidays/tests/test_access_rights.py
index 2d97aaf9377..8f36f6e7a98 100644
--- a/addons/hr_holidays/tests/test_access_rights.py
+++ b/addons/hr_holidays/tests/test_access_rights.py
@@ -12,61 +12,62 @@ from odoo.tools import mute_logger
 
 @tests.tagged('access_rights', 'post_install', '-at_install')
 class TestHrHolidaysAccessRightsCommon(TestHrHolidaysCommon):
-    def setUp(self):
-        super(TestHrHolidaysAccessRightsCommon, self).setUp()
-        self.leave_type = self.env['hr.leave.type'].create({
+    @classmethod
+    def setUpClass(cls):
+        super(TestHrHolidaysAccessRightsCommon, cls).setUpClass()
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'name': 'Unlimited',
             'leave_validation_type': 'hr',
             'requires_allocation': 'no',
         })
-        self.rd_dept.manager_id = False
-        self.hr_dept.manager_id = False
-        self.employee_emp.parent_id = False
-        self.employee_leave = self.env['hr.leave'].with_user(self.user_employee_id).create({
+        cls.rd_dept.manager_id = False
+        cls.hr_dept.manager_id = False
+        cls.employee_emp.parent_id = False
+        cls.employee_leave = cls.env['hr.leave'].with_user(cls.user_employee_id).create({
             'name': 'Test',
-            'holiday_status_id': self.leave_type.id,
-            'department_id': self.employee_emp.department_id.id,
-            'employee_id': self.employee_emp.id,
+            'holiday_status_id': cls.leave_type.id,
+            'department_id': cls.employee_emp.department_id.id,
+            'employee_id': cls.employee_emp.id,
             'date_from': datetime.now(),
             'date_to': datetime.now() + relativedelta(days=1),
             'number_of_days': 1,
         })
 
-        self.lt_no_validation = self.env['hr.leave.type'].create({
+        cls.lt_no_validation = cls.env['hr.leave.type'].create({
             'name': 'Validation = no_validation',
             'leave_validation_type': 'hr',
             'requires_allocation': 'no',
         })
 
-        self.lt_validation_hr = self.env['hr.leave.type'].create({
+        cls.lt_validation_hr = cls.env['hr.leave.type'].create({
             'name': 'Validation = HR',
             'leave_validation_type': 'hr',
             'requires_allocation': 'no',
         })
 
-        self.lt_validation_manager = self.env['hr.leave.type'].create({
+        cls.lt_validation_manager = cls.env['hr.leave.type'].create({
             'name': 'Validation = manager',
             'leave_validation_type': 'hr',
             'requires_allocation': 'no',
         })
 
-        self.lt_validation_both = self.env['hr.leave.type'].create({
+        cls.lt_validation_both = cls.env['hr.leave.type'].create({
             'name': 'Validation = both',
             'leave_validation_type': 'hr',
             'requires_allocation': 'no',
         })
 
-        self.draft_status = [
-            self.lt_validation_hr,
-            self.lt_validation_manager,
-            self.lt_validation_both
+        cls.draft_status = [
+            cls.lt_validation_hr,
+            cls.lt_validation_manager,
+            cls.lt_validation_both
         ]
 
-        self.confirm_status = [
-            self.lt_no_validation,
-            self.lt_validation_hr,
-            self.lt_validation_manager,
-            self.lt_validation_both
+        cls.confirm_status = [
+            cls.lt_no_validation,
+            cls.lt_validation_hr,
+            cls.lt_validation_manager,
+            cls.lt_validation_both
         ]
 
     def request_leave(self, user_id, date_from, number_of_days, values=None):
@@ -765,25 +766,26 @@ class TestAccessRightsUnlink(TestHrHolidaysAccessRightsCommon):
 
 class TestMultiCompany(TestHrHolidaysCommon):
 
-    def setUp(self):
-        super(TestMultiCompany, self).setUp()
-        self.new_company = self.env['res.company'].create({
+    @classmethod
+    def setUpClass(cls):
+        super(TestMultiCompany, cls).setUpClass()
+        cls.new_company = cls.env['res.company'].create({
             'name': 'Crocodile Dundee Company',
         })
-        self.leave_type = self.env['hr.leave.type'].create({
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'name': 'Unlimited - Company New',
-            'company_id': self.new_company.id,
+            'company_id': cls.new_company.id,
             'leave_validation_type': 'hr',
             'requires_allocation': 'no',
         })
-        self.rd_dept.manager_id = False
-        self.hr_dept.manager_id = False
+        cls.rd_dept.manager_id = False
+        cls.hr_dept.manager_id = False
 
-        self.employee_leave = self.env['hr.leave'].create({
+        cls.employee_leave = cls.env['hr.leave'].create({
             'name': 'Test',
-            'holiday_status_id': self.leave_type.id,
-            'department_id': self.employee_emp.department_id.id,
-            'employee_id': self.employee_emp.id,
+            'holiday_status_id': cls.leave_type.id,
+            'department_id': cls.employee_emp.department_id.id,
+            'employee_id': cls.employee_emp.id,
             'date_from': datetime.now(),
             'date_to': datetime.now() + relativedelta(days=1),
             'number_of_days': 1,
diff --git a/addons/hr_holidays/tests/test_accrual_allocations.py b/addons/hr_holidays/tests/test_accrual_allocations.py
index 3bad3559396..70cd0c47c65 100644
--- a/addons/hr_holidays/tests/test_accrual_allocations.py
+++ b/addons/hr_holidays/tests/test_accrual_allocations.py
@@ -12,9 +12,10 @@ from odoo.addons.hr_holidays.tests.common import TestHrHolidaysCommon
 
 @tagged('post_install', '-at_install')
 class TestAccrualAllocations(TestHrHolidaysCommon):
-    def setUp(self):
-        super(TestAccrualAllocations, self).setUp()
-        self.leave_type = self.env['hr.leave.type'].create({
+    @classmethod
+    def setUpClass(cls):
+        super(TestAccrualAllocations, cls).setUpClass()
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'name': 'Paid Time Off',
             'time_type': 'leave',
             'requires_allocation': 'yes',
diff --git a/addons/hr_holidays/tests/test_allocation_access_rights.py b/addons/hr_holidays/tests/test_allocation_access_rights.py
index b68ffc200dc..863f2dd6161 100644
--- a/addons/hr_holidays/tests/test_allocation_access_rights.py
+++ b/addons/hr_holidays/tests/test_allocation_access_rights.py
@@ -10,28 +10,29 @@ import time
 @tests.tagged('access_rights', 'post_install', '-at_install')
 class TestAllocationRights(TestHrHolidaysCommon):
 
-    def setUp(self):
-        super().setUp()
-        self.rd_dept.manager_id = False
-        self.hr_dept.manager_id = False
-        self.employee_emp.parent_id = False
-        self.employee_emp.leave_manager_id = False
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.rd_dept.manager_id = False
+        cls.hr_dept.manager_id = False
+        cls.employee_emp.parent_id = False
+        cls.employee_emp.leave_manager_id = False
 
-        self.lt_no_validation = self.env['hr.leave.type'].create({
+        cls.lt_no_validation = cls.env['hr.leave.type'].create({
             'name': 'Validation = HR',
             'allocation_validation_type': 'officer',
             'requires_allocation': 'no',
             'employee_requests': 'yes',
         })
 
-        self.lt_validation_manager = self.env['hr.leave.type'].create({
+        cls.lt_validation_manager = cls.env['hr.leave.type'].create({
             'name': 'Validation = manager',
             'allocation_validation_type': 'officer',
             'requires_allocation': 'yes',
             'employee_requests': 'yes',
         })
 
-        self.lt_allocation_manager = self.env['hr.leave.type'].create({
+        cls.lt_allocation_manager = cls.env['hr.leave.type'].create({
             'name': 'Validation = manager',
             'allocation_validation_type': 'set',
             'requires_allocation': 'yes',
@@ -85,11 +86,12 @@ class TestAccessRightsSimpleUser(TestAllocationRights):
 
 class TestAccessRightsEmployeeManager(TestAllocationRights):
 
-    def setUp(self):
-        super().setUp()
-        self.managed_employee = self.env['hr.employee'].create({
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.managed_employee = cls.env['hr.employee'].create({
             'name': 'Jolly Jumper',
-            'leave_manager_id': self.user_employee.id,
+            'leave_manager_id': cls.user_employee.id,
         })
 
     def test_manager_request_allocation_other(self):
diff --git a/addons/hr_holidays/tests/test_automatic_leave_dates.py b/addons/hr_holidays/tests/test_automatic_leave_dates.py
index 17089dfe5e9..87f554b7b3a 100644
--- a/addons/hr_holidays/tests/test_automatic_leave_dates.py
+++ b/addons/hr_holidays/tests/test_automatic_leave_dates.py
@@ -8,10 +8,11 @@ from odoo.exceptions import ValidationError
 
 
 class TestAutomaticLeaveDates(TestHrHolidaysCommon):
-    def setUp(self):
-        super(TestAutomaticLeaveDates, self).setUp()
+    @classmethod
+    def setUpClass(cls):
+        super(TestAutomaticLeaveDates, cls).setUpClass()
 
-        self.leave_type = self.env['hr.leave.type'].create({
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'name': 'Automatic Test',
             'time_type': 'leave',
             'requires_allocation': 'no',
diff --git a/addons/hr_holidays/tests/test_leave_requests.py b/addons/hr_holidays/tests/test_leave_requests.py
index bcf0e3af4cb..00c6687e2fa 100644
--- a/addons/hr_holidays/tests/test_leave_requests.py
+++ b/addons/hr_holidays/tests/test_leave_requests.py
@@ -27,43 +27,45 @@ class TestLeaveRequests(TestHrHolidaysCommon):
             self.assertEqual(holiday_status.virtual_remaining_leaves, vrl,
                              'hr_holidays: wrong type days computation')
 
-    def setUp(self):
-        super(TestLeaveRequests, self).setUp()
+    @classmethod
+    def setUpClass(cls):
+        super(TestLeaveRequests, cls).setUpClass()
 
         # Make sure we have the rights to create, validate and delete the leaves, leave types and allocations
-        LeaveType = self.env['hr.leave.type'].with_user(self.user_hrmanager_id).with_context(tracking_disable=True)
+        LeaveType = cls.env['hr.leave.type'].with_user(cls.user_hrmanager_id).with_context(tracking_disable=True)
 
-        self.holidays_type_1 = LeaveType.create({
+        cls.holidays_type_1 = LeaveType.create({
             'name': 'NotLimitedHR',
             'requires_allocation': 'no',
             'leave_validation_type': 'hr',
         })
-        self.holidays_type_2 = LeaveType.create({
+        cls.holidays_type_2 = LeaveType.create({
             'name': 'Limited',
             'requires_allocation': 'yes',
             'employee_requests': 'yes',
             'leave_validation_type': 'hr',
         })
-        self.holidays_type_3 = LeaveType.create({
+        cls.holidays_type_3 = LeaveType.create({
             'name': 'TimeNotLimited',
             'requires_allocation': 'no',
             'leave_validation_type': 'manager',
         })
 
-        self.set_employee_create_date(self.employee_emp_id, '2010-02-03 00:00:00')
-        self.set_employee_create_date(self.employee_hruser_id, '2010-02-03 00:00:00')
+        cls.set_employee_create_date(cls.employee_emp_id, '2010-02-03 00:00:00')
+        cls.set_employee_create_date(cls.employee_hruser_id, '2010-02-03 00:00:00')
 
-    def set_employee_create_date(self, id, newdate):
+    @classmethod
+    def set_employee_create_date(cls, _id, newdate):
         """ This method is a hack in order to be able to define/redefine the create_date
             of the employees.
             This is done in SQL because ORM does not allow to write onto the create_date field.
         """
-        self.env.cr.execute("""
+        cls.env.cr.execute("""
                        UPDATE
                        hr_employee
                        SET create_date = '%s'
                        WHERE id = %s
-                       """ % (newdate, id))
+                       """ % (newdate, _id))
 
     @mute_logger('odoo.models.unlink', 'odoo.addons.mail.models.mail_mail')
     def test_overlapping_requests(self):
diff --git a/addons/hr_holidays/tests/test_out_of_office.py b/addons/hr_holidays/tests/test_out_of_office.py
index a71fd55b3fc..485ff1523f8 100644
--- a/addons/hr_holidays/tests/test_out_of_office.py
+++ b/addons/hr_holidays/tests/test_out_of_office.py
@@ -13,9 +13,10 @@ from odoo.addons.hr_holidays.tests.common import TestHrHolidaysCommon
 @tagged('out_of_office')
 class TestOutOfOffice(TestHrHolidaysCommon):
 
-    def setUp(self):
-        super().setUp()
-        self.leave_type = self.env['hr.leave.type'].create({
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'name': 'Legal Leaves',
             'time_type': 'leave',
             'requires_allocation': 'no',
@@ -60,26 +61,27 @@ class TestOutOfOffice(TestHrHolidaysCommon):
 @tagged('out_of_office')
 class TestOutOfOfficePerformance(TestHrHolidaysCommon, TransactionCaseWithUserDemo):
 
-    def setUp(self):
-        super(TestOutOfOfficePerformance, self).setUp()
-        self.leave_type = self.env['hr.leave.type'].create({
+    @classmethod
+    def setUpClass(cls):
+        super(TestOutOfOfficePerformance, cls).setUpClass()
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'name': 'Legal Leaves',
             'time_type': 'leave',
             'requires_allocation': 'no',
         })
-        self.leave_date_end = (datetime.today() + relativedelta(days=3))
-        self.leave = self.env['hr.leave'].create({
+        cls.leave_date_end = (datetime.today() + relativedelta(days=3))
+        cls.leave = cls.env['hr.leave'].create({
             'name': 'Christmas',
-            'employee_id': self.employee_hruser_id,
-            'holiday_status_id': self.leave_type.id,
+            'employee_id': cls.employee_hruser_id,
+            'holiday_status_id': cls.leave_type.id,
             'date_from': (datetime.today() - relativedelta(days=1)),
             'date_to': (datetime.today() + relativedelta(days=3)),
             'number_of_days': 4,
         })
 
-        self.hr_user = self.employee_hruser.user_id
-        self.hr_partner = self.employee_hruser.user_id.partner_id
-        self.employer_partner = self.user_employee.partner_id
+        cls.hr_user = cls.employee_hruser.user_id
+        cls.hr_partner = cls.employee_hruser.user_id.partner_id
+        cls.employer_partner = cls.user_employee.partner_id
 
     @users('__system__', 'demo')
     @warmup
diff --git a/addons/hr_holidays/tests/test_res_partner.py b/addons/hr_holidays/tests/test_res_partner.py
index 806a93a5908..1e27e879526 100644
--- a/addons/hr_holidays/tests/test_res_partner.py
+++ b/addons/hr_holidays/tests/test_res_partner.py
@@ -12,43 +12,44 @@ from odoo.tools.misc import DEFAULT_SERVER_DATE_FORMAT
 @tagged('post_install', '-at_install')
 class TestPartner(TransactionCase):
 
-    def setUp(self):
-        super().setUp()
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
         # use a single value for today throughout the tests to avoid weird scenarios around midnight
-        self.today = date.today()
-        baseUser = self.env['res.users'].create({
+        cls.today = date.today()
+        baseUser = cls.env['res.users'].create({
             'email': 'e.e@example.com',
-            'groups_id': [Command.link(self.env.ref('base.group_user').id)],
+            'groups_id': [Command.link(cls.env.ref('base.group_user').id)],
             'login': 'emp',
             'name': 'Ernest Employee',
             'notification_type': 'inbox',
             'signature': '--\nErnest',
         })
-        self.partner = baseUser.partner_id
-        self.users = baseUser + self.env['res.users'].create({
+        cls.partner = baseUser.partner_id
+        cls.users = baseUser + cls.env['res.users'].create({
             'name': 'test1',
             'login': 'test1',
             'email': 'test1@example.com',
-            'partner_id': self.partner.id,
+            'partner_id': cls.partner.id,
         })
-        self.employees = self.env['hr.employee'].create([{
+        cls.employees = cls.env['hr.employee'].create([{
             'user_id': user.id,
-        } for user in self.users])
-        self.leave_type = self.env['hr.leave.type'].create({
+        } for user in cls.users])
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'requires_allocation': 'no',
             'name': 'Legal Leaves',
             'time_type': 'leave',
         })
-        self.leaves = self.env['hr.leave'].create([{
-            'date_from': self.today + relativedelta(days=-2),
-            'date_to': self.today + relativedelta(days=2),
-            'employee_id': self.employees[0].id,
-            'holiday_status_id': self.leave_type.id,
+        cls.leaves = cls.env['hr.leave'].create([{
+            'date_from': cls.today + relativedelta(days=-2),
+            'date_to': cls.today + relativedelta(days=2),
+            'employee_id': cls.employees[0].id,
+            'holiday_status_id': cls.leave_type.id,
         }, {
-            'date_from': self.today + relativedelta(days=-2),
-            'date_to': self.today + relativedelta(days=3),
-            'employee_id': self.employees[1].id,
-            'holiday_status_id': self.leave_type.id,
+            'date_from': cls.today + relativedelta(days=-2),
+            'date_to': cls.today + relativedelta(days=3),
+            'employee_id': cls.employees[1].id,
+            'holiday_status_id': cls.leave_type.id,
         }])
 
     def test_res_partner_mail_partner_format(self):
diff --git a/addons/hr_timesheet/tests/test_timesheet.py b/addons/hr_timesheet/tests/test_timesheet.py
index 63da1637bb5..c70d40cc54c 100644
--- a/addons/hr_timesheet/tests/test_timesheet.py
+++ b/addons/hr_timesheet/tests/test_timesheet.py
@@ -7,80 +7,81 @@ from odoo.exceptions import AccessError, UserError
 
 class TestCommonTimesheet(TransactionCase):
 
-    def setUp(self):
-        super(TestCommonTimesheet, self).setUp()
+    @classmethod
+    def setUpClass(cls):
+        super(TestCommonTimesheet, cls).setUpClass()
 
         # Crappy hack to disable the rule from timesheet grid, if it exists
         # The registry doesn't contain the field timesheet_manager_id.
         # but there is an ir.rule about it, crashing during its evaluation
-        rule = self.env.ref('timesheet_grid.hr_timesheet_rule_approver_update', raise_if_not_found=False)
+        rule = cls.env.ref('timesheet_grid.hr_timesheet_rule_approver_update', raise_if_not_found=False)
         if rule:
             rule.active = False
 
         # customer partner
-        self.partner = self.env['res.partner'].create({
+        cls.partner = cls.env['res.partner'].create({
             'name': 'Customer Task',
             'email': 'customer@task.com',
             'phone': '42',
         })
 
-        self.analytic_account = self.env['account.analytic.account'].create({
+        cls.analytic_account = cls.env['account.analytic.account'].create({
             'name': 'Analytic Account for Test Customer',
-            'partner_id': self.partner.id,
+            'partner_id': cls.partner.id,
             'code': 'TEST'
         })
 
         # project and tasks
-        self.project_customer = self.env['project.project'].create({
+        cls.project_customer = cls.env['project.project'].create({
             'name': 'Project X',
             'allow_timesheets': True,
-            'partner_id': self.partner.id,
-            'analytic_account_id': self.analytic_account.id,
+            'partner_id': cls.partner.id,
+            'analytic_account_id': cls.analytic_account.id,
         })
-        self.task1 = self.env['project.task'].create({
+        cls.task1 = cls.env['project.task'].create({
             'name': 'Task One',
             'priority': '0',
             'kanban_state': 'normal',
-            'project_id': self.project_customer.id,
-            'partner_id': self.partner.id,
+            'project_id': cls.project_customer.id,
+            'partner_id': cls.partner.id,
         })
-        self.task2 = self.env['project.task'].create({
+        cls.task2 = cls.env['project.task'].create({
             'name': 'Task Two',
             'priority': '1',
             'kanban_state': 'done',
-            'project_id': self.project_customer.id,
+            'project_id': cls.project_customer.id,
         })
         # users
-        self.user_employee = self.env['res.users'].create({
+        cls.user_employee = cls.env['res.users'].create({
             'name': 'User Employee',
             'login': 'user_employee',
             'email': 'useremployee@test.com',
-            'groups_id': [(6, 0, [self.ref('hr_timesheet.group_hr_timesheet_user')])],
+            'groups_id': [(6, 0, [cls.env.ref('hr_timesheet.group_hr_timesheet_user').id])],
         })
-        self.user_employee2 = self.env['res.users'].create({
+        cls.user_employee2 = cls.env['res.users'].create({
             'name': 'User Employee 2',
             'login': 'user_employee2',
             'email': 'useremployee2@test.com',
-            'groups_id': [(6, 0, [self.ref('hr_timesheet.group_hr_timesheet_user')])],
+            'groups_id': [(6, 0, [cls.env.ref('hr_timesheet.group_hr_timesheet_user').id])],
         })
-        self.user_manager = self.env['res.users'].create({
+        cls.user_manager = cls.env['res.users'].create({
             'name': 'User Officer',
             'login': 'user_manager',
             'email': 'usermanager@test.com',
-            'groups_id': [(6, 0, [self.ref('hr_timesheet.group_timesheet_manager')])],
+            'groups_id': [(6, 0, [cls.env.ref('hr_timesheet.group_timesheet_manager').id])],
         })
         # employees
-        self.empl_employee = self.env['hr.employee'].create({
+        cls.empl_employee = cls.env['hr.employee'].create({
             'name': 'User Empl Employee',
-            'user_id': self.user_employee.id,
+            'user_id': cls.user_employee.id,
         })
-        self.empl_employee2 = self.env['hr.employee'].create({
+        cls.empl_employee2 = cls.env['hr.employee'].create({
             'name': 'User Empl Employee 2',
-            'user_id': self.user_employee2.id,
+            'user_id': cls.user_employee2.id,
         })
-        self.empl_manager = self.env['hr.employee'].create({
+        cls.empl_manager = cls.env['hr.employee'].create({
             'name': 'User Empl Officer',
-            'user_id': self.user_manager.id,
+            'user_id': cls.user_manager.id,
         })
 
 class TestTimesheet(TestCommonTimesheet):
diff --git a/addons/hr_work_entry_contract/tests/common.py b/addons/hr_work_entry_contract/tests/common.py
index 3e9e38a22d3..3c19cc14006 100644
--- a/addons/hr_work_entry_contract/tests/common.py
+++ b/addons/hr_work_entry_contract/tests/common.py
@@ -57,11 +57,22 @@ class TestWorkEntryBase(TransactionCase):
 
     def create_work_entry(self, start, stop, work_entry_type=None):
         work_entry_type = work_entry_type or self.work_entry_type
-        return self.env['hr.work.entry'].create({
-            'contract_id': self.richard_emp.contract_ids[0].id,
-            'name': "Work entry %s-%s" % (start, stop),
-            'date_start': start,
-            'date_stop': stop,
-            'employee_id': self.richard_emp.id,
-            'work_entry_type_id': work_entry_type.id,
-        })
+        return self.create_work_entries([(start, stop, work_entry_type)])
+
+    def create_work_entries(self, intervals):
+        default_work_entry_type = self.work_entry_type
+        create_vals = []
+        for interval in intervals:
+            start = interval[0]
+            stop = interval[1]
+            work_entry_type = interval[2] if len(interval) == 3\
+                else default_work_entry_type
+            create_vals.append({
+                'contract_id': self.richard_emp.contract_ids[0].id,
+                'name': 'Work entry %s-%s' % (start, stop),
+                'date_start': start,
+                'date_stop': stop,
+                'employee_id': self.richard_emp.id,
+                'work_entry_type_id': work_entry_type.id,
+            })
+        return self.env['hr.work.entry'].create(create_vals)
diff --git a/addons/hr_work_entry_contract/tests/test_work_entry.py b/addons/hr_work_entry_contract/tests/test_work_entry.py
index 7e5932f3fc8..14bec1f00c2 100644
--- a/addons/hr_work_entry_contract/tests/test_work_entry.py
+++ b/addons/hr_work_entry_contract/tests/test_work_entry.py
@@ -13,23 +13,25 @@ from odoo.addons.hr_work_entry_contract.tests.common import TestWorkEntryBase
 
 @tagged('work_entry')
 class TestWorkEntry(TestWorkEntryBase):
-    def setUp(self):
-        super(TestWorkEntry, self).setUp()
-        self.tz = pytz.timezone(self.richard_emp.tz)
-        self.start = datetime(2015, 11, 1, 1, 0, 0)
-        self.end = datetime(2015, 11, 30, 23, 59, 59)
-        self.resource_calendar_id = self.env['resource.calendar'].create({'name': 'My Calendar'})
-        contract = self.env['hr.contract'].create({
-            'date_start': self.start.date() - relativedelta(days=5),
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestWorkEntry, cls).setUpClass()
+        cls.tz = pytz.timezone(cls.richard_emp.tz)
+        cls.start = datetime(2015, 11, 1, 1, 0, 0)
+        cls.end = datetime(2015, 11, 30, 23, 59, 59)
+        cls.resource_calendar_id = cls.env['resource.calendar'].create({'name': 'My Calendar'})
+        contract = cls.env['hr.contract'].create({
+            'date_start': cls.start.date() - relativedelta(days=5),
             'name': 'dodo',
-            'resource_calendar_id': self.resource_calendar_id.id,
+            'resource_calendar_id': cls.resource_calendar_id.id,
             'wage': 1000,
-            'employee_id': self.richard_emp.id,
+            'employee_id': cls.richard_emp.id,
             'state': 'open',
-            'date_generated_from': self.end.date() + relativedelta(days=5),
+            'date_generated_from': cls.end.date() + relativedelta(days=5),
         })
-        self.richard_emp.resource_calendar_id = self.resource_calendar_id
-        self.richard_emp.contract_id = contract
+        cls.richard_emp.resource_calendar_id = cls.resource_calendar_id
+        cls.richard_emp.contract_id = contract
 
     def test_no_duplicate(self):
         self.richard_emp.generate_work_entries(self.start, self.end)
@@ -102,13 +104,23 @@ class TestWorkEntry(TestWorkEntryBase):
     def test_outside_calendar(self):
         """ Test leave work entries outside schedule are conflicting """
         # Outside but not a leave
-        work_entry_1 = self.create_work_entry(datetime(2018, 10, 10, 3, 0), datetime(2018, 10, 10, 4, 0))
-        # Outside and a leave
-        work_entry_2 = self.create_work_entry(datetime(2018, 10, 10, 1, 0), datetime(2018, 10, 10, 2, 0), work_entry_type=self.work_entry_type_leave)
-        # Overlapping and a leave
-        work_entry_3 = self.create_work_entry(datetime(2018, 10, 10, 7, 0), datetime(2018, 10, 10, 10, 0), work_entry_type=self.work_entry_type_leave)
-        # Overlapping and not a leave
-        work_entry_4 = self.create_work_entry(datetime(2018, 10, 10, 11, 0), datetime(2018, 10, 10, 13, 0))
+        # work_entry_1 = self.create_work_entry(datetime(2018, 10, 10, 3, 0), datetime(2018, 10, 10, 4, 0))
+        # # Outside and a leave
+        # work_entry_2 = self.create_work_entry(datetime(2018, 10, 10, 1, 0), datetime(2018, 10, 10, 2, 0), work_entry_type=self.work_entry_type_leave)
+        # # Overlapping and a leave
+        # work_entry_3 = self.create_work_entry(datetime(2018, 10, 10, 7, 0), datetime(2018, 10, 10, 10, 0), work_entry_type=self.work_entry_type_leave)
+        # # Overlapping and not a leave
+        # work_entry_4 = self.create_work_entry(datetime(2018, 10, 10, 11, 0), datetime(2018, 10, 10, 13, 0))
+        work_entry_1, work_entry_2, work_entry_3, work_entry_4 = self.create_work_entries([
+            # Outside but not a leave
+            (datetime(2018, 10, 10, 3, 0), datetime(2018, 10, 10, 4, 0)),
+            # Outside and a leave
+            (datetime(2018, 10, 10, 1, 0), datetime(2018, 10, 10, 2, 0), self.work_entry_type_leave),
+            # Overlapping and a leave
+            (datetime(2018, 10, 10, 7, 0), datetime(2018, 10, 10, 10, 0), self.work_entry_type_leave),
+            # Overlapping and not a leave
+            (datetime(2018, 10, 10, 11, 0), datetime(2018, 10, 10, 13, 0)),
+        ])
         (work_entry_1 | work_entry_2 | work_entry_3 | work_entry_4)._mark_leaves_outside_schedule()
         self.assertEqual(work_entry_2.state, 'conflict', "It should conflict")
         self.assertNotEqual(work_entry_1.state, 'conflict', "It should not conflict")
@@ -117,8 +129,12 @@ class TestWorkEntry(TestWorkEntryBase):
 
     def test_write_conflict(self):
         """ Test updating work entries dates recomputes conflicts """
-        work_entry_1 = self.create_work_entry(datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0))
-        work_entry_2 = self.create_work_entry(datetime(2018, 10, 10, 12, 0), datetime(2018, 10, 10, 18, 0))
+        # work_entry_1 = self.create_work_entry(datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0))
+        # work_entry_2 = self.create_work_entry(datetime(2018, 10, 10, 12, 0), datetime(2018, 10, 10, 18, 0))
+        work_entry_1, work_entry_2 = self.create_work_entries([
+            (datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0)),
+            (datetime(2018, 10, 10, 12, 0), datetime(2018, 10, 10, 18, 0)),
+        ])
         self.assertNotEqual(work_entry_1.state, 'conflict', "It should not conflict")
         self.assertNotEqual(work_entry_2.state, 'conflict', "It should not conflict")
         work_entry_1.date_stop = datetime(2018, 10, 10, 14, 0)
@@ -131,9 +147,14 @@ class TestWorkEntry(TestWorkEntryBase):
 
     def test_write_move(self):
         """ Test completely moving a work entry recomputes conflicts """
-        work_entry_1 = self.create_work_entry(datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0))
-        work_entry_2 = self.create_work_entry(datetime(2018, 10, 18, 9, 0), datetime(2018, 10, 18, 12, 0))
-        work_entry_3 = self.create_work_entry(datetime(2018, 10, 18, 10, 0), datetime(2018, 10, 18, 12, 0))
+        # work_entry_1 = self.create_work_entry(datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0))
+        # work_entry_2 = self.create_work_entry(datetime(2018, 10, 18, 9, 0), datetime(2018, 10, 18, 12, 0))
+        # work_entry_3 = self.create_work_entry(datetime(2018, 10, 18, 10, 0), datetime(2018, 10, 18, 12, 0))
+        work_entry_1, work_entry_2, work_entry_3 = self.create_work_entries([
+            (datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0)),
+            (datetime(2018, 10, 18, 9, 0), datetime(2018, 10, 18, 12, 0)),
+            (datetime(2018, 10, 18, 10, 0), datetime(2018, 10, 18, 12, 0)),
+        ])
         work_entry_2.write({
             'date_start': datetime(2018, 10, 10, 9, 0),
             'date_stop': datetime(2018, 10, 10, 10, 0),
@@ -152,8 +173,12 @@ class TestWorkEntry(TestWorkEntryBase):
 
     def test_unarchive_conflict(self):
         """ Test archive/unarchive a work entry recomputes conflicts """
-        work_entry_1 = self.create_work_entry(datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0))
-        work_entry_2 = self.create_work_entry(datetime(2018, 10, 10, 10, 0), datetime(2018, 10, 10, 18, 0))
+        # work_entry_1 = self.create_work_entry(datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0))
+        # work_entry_2 = self.create_work_entry(datetime(2018, 10, 10, 10, 0), datetime(2018, 10, 10, 18, 0))
+        work_entry_1, work_entry_2 = self.create_work_entries([
+            (datetime(2018, 10, 10, 9, 0), datetime(2018, 10, 10, 12, 0)),
+            (datetime(2018, 10, 10, 10, 0), datetime(2018, 10, 10, 18, 0)),
+        ])
         work_entry_2.active = False
         self.assertNotEqual(work_entry_1.state, 'conflict', "It should not conflict")
         self.assertEqual(work_entry_2.state, 'cancelled', "It should be cancelled")
diff --git a/addons/hr_work_entry_holidays/tests/test_multi_contract.py b/addons/hr_work_entry_holidays/tests/test_multi_contract.py
index 23ac048dfe1..58f736e6470 100644
--- a/addons/hr_work_entry_holidays/tests/test_multi_contract.py
+++ b/addons/hr_work_entry_holidays/tests/test_multi_contract.py
@@ -8,13 +8,14 @@ from odoo.addons.hr_work_entry_holidays.tests.common import TestWorkEntryHoliday
 
 class TestWorkEntryHolidaysMultiContract(TestWorkEntryHolidaysBase):
 
-    def setUp(self):
-        super().setUp()
-        self.leave_type = self.env['hr.leave.type'].create({
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'name': 'Legal Leaves',
             'time_type': 'leave',
             'requires_allocation': 'no',
-            'work_entry_type_id': self.work_entry_type_leave.id
+            'work_entry_type_id': cls.work_entry_type_leave.id
         })
 
     def create_leave(self, start, end):
diff --git a/addons/hr_work_entry_holidays/tests/test_payslip_holidays_computation.py b/addons/hr_work_entry_holidays/tests/test_payslip_holidays_computation.py
index 4a8ffa0d808..7064e839dca 100644
--- a/addons/hr_work_entry_holidays/tests/test_payslip_holidays_computation.py
+++ b/addons/hr_work_entry_holidays/tests/test_payslip_holidays_computation.py
@@ -8,14 +8,15 @@ from odoo.addons.hr_work_entry_holidays.tests.common import TestWorkEntryHoliday
 
 class TestPayslipHolidaysComputation(TestWorkEntryHolidaysBase):
 
-    def setUp(self):
-        super().setUp()
+    @classmethod
+    def setUpClass(cls):
+        super().setUpClass()
 
-        self.leave_type = self.env['hr.leave.type'].create({
+        cls.leave_type = cls.env['hr.leave.type'].create({
             'name': 'Legal Leaves',
             'time_type': 'leave',
             'requires_allocation': 'no',
-            'work_entry_type_id': self.work_entry_type_leave.id
+            'work_entry_type_id': cls.work_entry_type_leave.id
         })
 
     def test_work_data(self):
diff --git a/addons/hr_work_entry_holidays/tests/test_work_entry.py b/addons/hr_work_entry_holidays/tests/test_work_entry.py
index c229a8a3d4f..4dc056e7bc6 100644
--- a/addons/hr_work_entry_holidays/tests/test_work_entry.py
+++ b/addons/hr_work_entry_holidays/tests/test_work_entry.py
@@ -12,23 +12,24 @@ from odoo.addons.hr_work_entry_holidays.tests.common import TestWorkEntryHoliday
 
 @tagged('work_entry')
 class TestWorkeEntryHolidaysWorkEntry(TestWorkEntryHolidaysBase):
-    def setUp(self):
-        super(TestWorkeEntryHolidaysWorkEntry, self).setUp()
-        self.tz = pytz.timezone(self.richard_emp.tz)
-        self.start = datetime(2015, 11, 1, 1, 0, 0)
-        self.end = datetime(2015, 11, 30, 23, 59, 59)
-        self.resource_calendar_id = self.env['resource.calendar'].create({'name': 'Zboub'})
-        contract = self.env['hr.contract'].create({
-            'date_start': self.start.date() - relativedelta(days=5),
+    @classmethod
+    def setUpClass(cls):
+        super(TestWorkeEntryHolidaysWorkEntry, cls).setUpClass()
+        cls.tz = pytz.timezone(cls.richard_emp.tz)
+        cls.start = datetime(2015, 11, 1, 1, 0, 0)
+        cls.end = datetime(2015, 11, 30, 23, 59, 59)
+        cls.resource_calendar_id = cls.env['resource.calendar'].create({'name': 'Zboub'})
+        contract = cls.env['hr.contract'].create({
+            'date_start': cls.start.date() - relativedelta(days=5),
             'name': 'dodo',
-            'resource_calendar_id': self.resource_calendar_id.id,
+            'resource_calendar_id': cls.resource_calendar_id.id,
             'wage': 1000,
-            'employee_id': self.richard_emp.id,
+            'employee_id': cls.richard_emp.id,
             'state': 'open',
-            'date_generated_from': self.end.date() + relativedelta(days=5),
+            'date_generated_from': cls.end.date() + relativedelta(days=5),
         })
-        self.richard_emp.resource_calendar_id = self.resource_calendar_id
-        self.richard_emp.contract_id = contract
+        cls.richard_emp.resource_calendar_id = cls.resource_calendar_id
+        cls.richard_emp.contract_id = contract
 
     def test_validate_non_approved_leave_work_entry(self):
         work_entry1 = self.env['hr.work.entry'].create({