diff --git a/awx/api/serializers.py b/awx/api/serializers.py
index 5c3edddb52..b466d1e91d 100644
--- a/awx/api/serializers.py
+++ b/awx/api/serializers.py
@@ -2073,7 +2073,7 @@ class InventorySourceSerializer(UnifiedJobTemplateSerializer, InventorySourceOpt
 
     class Meta:
         model = InventorySource
-        fields = ('*', 'name', 'inventory', 'update_on_launch', 'update_cache_timeout', 'source_project', 'update_on_project_update') + (
+        fields = ('*', 'name', 'inventory', 'update_on_launch', 'update_cache_timeout', 'source_project') + (
             'last_update_failed',
             'last_updated',
         )  # Backwards compatibility.
@@ -2136,11 +2136,6 @@ class InventorySourceSerializer(UnifiedJobTemplateSerializer, InventorySourceOpt
             raise serializers.ValidationError(_("Cannot use manual project for SCM-based inventory."))
         return value
 
-    def validate_update_on_project_update(self, value):
-        if value and self.instance and self.instance.schedules.exists():
-            raise serializers.ValidationError(_("Setting not compatible with existing schedules."))
-        return value
-
     def validate_inventory(self, value):
         if value and value.kind == 'smart':
             raise serializers.ValidationError({"detail": _("Cannot create Inventory Source for Smart Inventory")})
@@ -2191,7 +2186,7 @@ class InventorySourceSerializer(UnifiedJobTemplateSerializer, InventorySourceOpt
             if ('source' in attrs or 'source_project' in attrs) and get_field_from_model_or_attrs('source_project') is None:
                 raise serializers.ValidationError({"source_project": _("Project required for scm type sources.")})
         else:
-            redundant_scm_fields = list(filter(lambda x: attrs.get(x, None), ['source_project', 'source_path', 'update_on_project_update']))
+            redundant_scm_fields = list(filter(lambda x: attrs.get(x, None), ['source_project', 'source_path']))
             if redundant_scm_fields:
                 raise serializers.ValidationError({"detail": _("Cannot set %s if not SCM type." % ' '.join(redundant_scm_fields))})
 
@@ -4745,13 +4740,6 @@ class ScheduleSerializer(LaunchConfigurationBaseSerializer, SchedulePreviewSeria
             raise serializers.ValidationError(_('Inventory Source must be a cloud resource.'))
         elif type(value) == Project and value.scm_type == '':
             raise serializers.ValidationError(_('Manual Project cannot have a schedule set.'))
-        elif type(value) == InventorySource and value.source == 'scm' and value.update_on_project_update:
-            raise serializers.ValidationError(
-                _(
-                    'Inventory sources with `update_on_project_update` cannot be scheduled. '
-                    'Schedule its source project `{}` instead.'.format(value.source_project.name)
-                )
-            )
         return value
 
     def validate(self, attrs):
diff --git a/awx/api/views/__init__.py b/awx/api/views/__init__.py
index 54dcf7034b..0d46c05834 100644
--- a/awx/api/views/__init__.py
+++ b/awx/api/views/__init__.py
@@ -115,7 +115,6 @@ from awx.api.metadata import RoleMetadata
 from awx.main.constants import ACTIVE_STATES, SURVEY_TYPE_MAPPING
 from awx.main.scheduler.dag_workflow import WorkflowDAG
 from awx.api.views.mixin import (
-    ControlledByScmMixin,
     InstanceGroupMembershipMixin,
     OrganizationCountsMixin,
     RelatedJobsPreventDeleteMixin,
@@ -1675,7 +1674,7 @@ class HostList(HostRelatedSearchMixin, ListCreateAPIView):
             return Response(dict(error=_(str(e))), status=status.HTTP_400_BAD_REQUEST)
 
 
-class HostDetail(RelatedJobsPreventDeleteMixin, ControlledByScmMixin, RetrieveUpdateDestroyAPIView):
+class HostDetail(RelatedJobsPreventDeleteMixin, RetrieveUpdateDestroyAPIView):
 
     always_allow_superuser = False
     model = models.Host
@@ -1709,7 +1708,7 @@ class InventoryHostsList(HostRelatedSearchMixin, SubListCreateAttachDetachAPIVie
         return qs
 
 
-class HostGroupsList(ControlledByScmMixin, SubListCreateAttachDetachAPIView):
+class HostGroupsList(SubListCreateAttachDetachAPIView):
     '''the list of groups a host is directly a member of'''
 
     model = models.Group
@@ -1825,7 +1824,7 @@ class EnforceParentRelationshipMixin(object):
         return super(EnforceParentRelationshipMixin, self).create(request, *args, **kwargs)
 
 
-class GroupChildrenList(ControlledByScmMixin, EnforceParentRelationshipMixin, SubListCreateAttachDetachAPIView):
+class GroupChildrenList(EnforceParentRelationshipMixin, SubListCreateAttachDetachAPIView):
 
     model = models.Group
     serializer_class = serializers.GroupSerializer
@@ -1871,7 +1870,7 @@ class GroupPotentialChildrenList(SubListAPIView):
         return qs.exclude(pk__in=except_pks)
 
 
-class GroupHostsList(HostRelatedSearchMixin, ControlledByScmMixin, SubListCreateAttachDetachAPIView):
+class GroupHostsList(HostRelatedSearchMixin, SubListCreateAttachDetachAPIView):
     '''the list of hosts directly below a group'''
 
     model = models.Host
@@ -1935,7 +1934,7 @@ class GroupActivityStreamList(SubListAPIView):
         return qs.filter(Q(group=parent) | Q(host__in=parent.hosts.all()))
 
 
-class GroupDetail(RelatedJobsPreventDeleteMixin, ControlledByScmMixin, RetrieveUpdateDestroyAPIView):
+class GroupDetail(RelatedJobsPreventDeleteMixin, RetrieveUpdateDestroyAPIView):
 
     model = models.Group
     serializer_class = serializers.GroupSerializer
diff --git a/awx/api/views/inventory.py b/awx/api/views/inventory.py
index 43815ae565..65e59790ac 100644
--- a/awx/api/views/inventory.py
+++ b/awx/api/views/inventory.py
@@ -41,7 +41,7 @@ from awx.api.serializers import (
     JobTemplateSerializer,
     LabelSerializer,
 )
-from awx.api.views.mixin import RelatedJobsPreventDeleteMixin, ControlledByScmMixin
+from awx.api.views.mixin import RelatedJobsPreventDeleteMixin
 
 from awx.api.pagination import UnifiedJobEventPagination
 
@@ -75,7 +75,7 @@ class InventoryList(ListCreateAPIView):
     serializer_class = InventorySerializer
 
 
-class InventoryDetail(RelatedJobsPreventDeleteMixin, ControlledByScmMixin, RetrieveUpdateDestroyAPIView):
+class InventoryDetail(RelatedJobsPreventDeleteMixin, RetrieveUpdateDestroyAPIView):
 
     model = Inventory
     serializer_class = InventorySerializer
diff --git a/awx/api/views/mixin.py b/awx/api/views/mixin.py
index a0a679d4e5..63762c1634 100644
--- a/awx/api/views/mixin.py
+++ b/awx/api/views/mixin.py
@@ -10,13 +10,12 @@ from django.shortcuts import get_object_or_404
 from django.utils.timezone import now
 from django.utils.translation import gettext_lazy as _
 
-from rest_framework.permissions import SAFE_METHODS
 from rest_framework.exceptions import PermissionDenied
 from rest_framework.response import Response
 from rest_framework import status
 
 from awx.main.constants import ACTIVE_STATES
-from awx.main.utils import get_object_or_400, parse_yaml_or_json
+from awx.main.utils import get_object_or_400
 from awx.main.models.ha import Instance, InstanceGroup
 from awx.main.models.organization import Team
 from awx.main.models.projects import Project
@@ -186,35 +185,6 @@ class OrganizationCountsMixin(object):
         return full_context
 
 
-class ControlledByScmMixin(object):
-    """
-    Special method to reset SCM inventory commit hash
-    if anything that it manages changes.
-    """
-
-    def _reset_inv_src_rev(self, obj):
-        if self.request.method in SAFE_METHODS or not obj:
-            return
-        project_following_sources = obj.inventory_sources.filter(update_on_project_update=True, source='scm')
-        if project_following_sources:
-            # Allow inventory changes unrelated to variables
-            if self.model == Inventory and (
-                not self.request or not self.request.data or parse_yaml_or_json(self.request.data.get('variables', '')) == parse_yaml_or_json(obj.variables)
-            ):
-                return
-            project_following_sources.update(scm_last_revision='')
-
-    def get_object(self):
-        obj = super(ControlledByScmMixin, self).get_object()
-        self._reset_inv_src_rev(obj)
-        return obj
-
-    def get_parent_object(self):
-        obj = super(ControlledByScmMixin, self).get_parent_object()
-        self._reset_inv_src_rev(obj)
-        return obj
-
-
 class NoTruncateMixin(object):
     def get_serializer_context(self):
         context = super().get_serializer_context()
diff --git a/awx/main/migrations/0164_remove_inventorysource_update_on_project_update.py b/awx/main/migrations/0164_remove_inventorysource_update_on_project_update.py
new file mode 100644
index 0000000000..59c4bdf839
--- /dev/null
+++ b/awx/main/migrations/0164_remove_inventorysource_update_on_project_update.py
@@ -0,0 +1,40 @@
+# Generated by Django 3.2.13 on 2022-06-21 21:29
+
+from django.db import migrations
+import logging
+
+logger = logging.getLogger("awx")
+
+
+def forwards(apps, schema_editor):
+    InventorySource = apps.get_model('main', 'InventorySource')
+    sources = InventorySource.objects.filter(update_on_project_update=True)
+    for src in sources:
+        if src.update_on_launch == False:
+            src.update_on_launch = True
+            src.save(update_fields=['update_on_launch'])
+            logger.info(f"Setting update_on_launch to True for {src}")
+        proj = src.source_project
+        if proj and proj.scm_update_on_launch is False:
+            proj.scm_update_on_launch = True
+            proj.save(update_fields=['scm_update_on_launch'])
+            logger.warning(f"Setting scm_update_on_launch to True for {proj}")
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('main', '0163_convert_job_tags_to_textfield'),
+    ]
+
+    operations = [
+        migrations.RunPython(forwards, migrations.RunPython.noop),
+        migrations.RemoveField(
+            model_name='inventorysource',
+            name='scm_last_revision',
+        ),
+        migrations.RemoveField(
+            model_name='inventorysource',
+            name='update_on_project_update',
+        ),
+    ]
diff --git a/awx/main/models/inventory.py b/awx/main/models/inventory.py
index 14e7477461..9a386db9c2 100644
--- a/awx/main/models/inventory.py
+++ b/awx/main/models/inventory.py
@@ -985,22 +985,11 @@ class InventorySource(UnifiedJobTemplate, InventorySourceOptions, CustomVirtualE
         default=None,
         null=True,
     )
-    scm_last_revision = models.CharField(
-        max_length=1024,
-        blank=True,
-        default='',
-        editable=False,
-    )
-    update_on_project_update = models.BooleanField(
-        default=False,
-        help_text=_(
-            'This field is deprecated and will be removed in a future release. '
-            'In future release, functionality will be migrated to source project update_on_launch.'
-        ),
-    )
+
     update_on_launch = models.BooleanField(
         default=False,
     )
+
     update_cache_timeout = models.PositiveIntegerField(
         default=0,
     )
@@ -1038,14 +1027,6 @@ class InventorySource(UnifiedJobTemplate, InventorySourceOptions, CustomVirtualE
                 self.name = 'inventory source (%s)' % replace_text
             if 'name' not in update_fields:
                 update_fields.append('name')
-        # Reset revision if SCM source has changed parameters
-        if self.source == 'scm' and not is_new_instance:
-            before_is = self.__class__.objects.get(pk=self.pk)
-            if before_is.source_path != self.source_path or before_is.source_project_id != self.source_project_id:
-                # Reset the scm_revision if file changed to force update
-                self.scm_last_revision = ''
-                if 'scm_last_revision' not in update_fields:
-                    update_fields.append('scm_last_revision')
 
         # Do the actual save.
         super(InventorySource, self).save(*args, **kwargs)
@@ -1054,10 +1035,6 @@ class InventorySource(UnifiedJobTemplate, InventorySourceOptions, CustomVirtualE
         if replace_text in self.name:
             self.name = self.name.replace(replace_text, str(self.pk))
             super(InventorySource, self).save(update_fields=['name'])
-        if self.source == 'scm' and is_new_instance and self.update_on_project_update:
-            # Schedule a new Project update if one is not already queued
-            if self.source_project and not self.source_project.project_updates.filter(status__in=['new', 'pending', 'waiting']).exists():
-                self.update()
         if not getattr(_inventory_updates, 'is_updating', False):
             if self.inventory is not None:
                 self.inventory.update_computed_fields()
@@ -1147,25 +1124,6 @@ class InventorySource(UnifiedJobTemplate, InventorySourceOptions, CustomVirtualE
             )
         return dict(error=list(error_notification_templates), started=list(started_notification_templates), success=list(success_notification_templates))
 
-    def clean_update_on_project_update(self):
-        if (
-            self.update_on_project_update is True
-            and self.source == 'scm'
-            and InventorySource.objects.filter(Q(inventory=self.inventory, update_on_project_update=True, source='scm') & ~Q(id=self.id)).exists()
-        ):
-            raise ValidationError(_("More than one SCM-based inventory source with update on project update per-inventory not allowed."))
-        return self.update_on_project_update
-
-    def clean_update_on_launch(self):
-        if self.update_on_project_update is True and self.source == 'scm' and self.update_on_launch is True:
-            raise ValidationError(
-                _(
-                    "Cannot update SCM-based inventory source on launch if set to update on project update. "
-                    "Instead, configure the corresponding source project to update on launch."
-                )
-            )
-        return self.update_on_launch
-
     def clean_source_path(self):
         if self.source != 'scm' and self.source_path:
             raise ValidationError(_("Cannot set source_path if not SCM type."))
@@ -1301,13 +1259,6 @@ class InventoryUpdate(UnifiedJob, InventorySourceOptions, JobNotificationMixin,
             return self.global_instance_groups
         return selected_groups
 
-    def cancel(self, job_explanation=None, is_chain=False):
-        res = super(InventoryUpdate, self).cancel(job_explanation=job_explanation, is_chain=is_chain)
-        if res:
-            if self.launch_type != 'scm' and self.source_project_update:
-                self.source_project_update.cancel(job_explanation=job_explanation)
-        return res
-
 
 class CustomInventoryScript(CommonModelNameNotUnique, ResourceMixin):
     class Meta:
diff --git a/awx/main/models/unified_jobs.py b/awx/main/models/unified_jobs.py
index 47794a7ef8..8a53fb5a19 100644
--- a/awx/main/models/unified_jobs.py
+++ b/awx/main/models/unified_jobs.py
@@ -533,7 +533,7 @@ class UnifiedJob(
         ('workflow', _('Workflow')),  # Job was started from a workflow job.
         ('webhook', _('Webhook')),  # Job was started from a webhook event.
         ('sync', _('Sync')),  # Job was started from a project sync.
-        ('scm', _('SCM Update')),  # Job was created as an Inventory SCM sync.
+        ('scm', _('SCM Update')),  # (deprecated) Job was created as an Inventory SCM sync.
     ]
 
     PASSWORD_FIELDS = ('start_args',)
diff --git a/awx/main/tasks/jobs.py b/awx/main/tasks/jobs.py
index 2963af669c..9c58e1eebe 100644
--- a/awx/main/tasks/jobs.py
+++ b/awx/main/tasks/jobs.py
@@ -19,7 +19,6 @@ from uuid import uuid4
 
 # Django
 from django.conf import settings
-from django.db import transaction
 
 
 # Runner
@@ -34,7 +33,6 @@ from gitdb.exc import BadName as BadGitName
 from awx.main.dispatch.publish import task
 from awx.main.dispatch import get_local_queuename
 from awx.main.constants import (
-    ACTIVE_STATES,
     PRIVILEGE_ESCALATION_METHODS,
     STANDARD_INVENTORY_UPDATE_ENV,
     JOB_FOLDER_PREFIX,
@@ -1168,64 +1166,6 @@ class RunProjectUpdate(BaseTask):
         d[r'^Are you sure you want to continue connecting \(yes/no\)\?\s*?$'] = 'yes'
         return d
 
-    def _update_dependent_inventories(self, project_update, dependent_inventory_sources):
-        scm_revision = project_update.project.scm_revision
-        inv_update_class = InventoryUpdate._get_task_class()
-        for inv_src in dependent_inventory_sources:
-            if not inv_src.update_on_project_update:
-                continue
-            if inv_src.scm_last_revision == scm_revision:
-                logger.debug('Skipping SCM inventory update for `{}` because ' 'project has not changed.'.format(inv_src.name))
-                continue
-            logger.debug('Local dependent inventory update for `{}`.'.format(inv_src.name))
-            with transaction.atomic():
-                if InventoryUpdate.objects.filter(inventory_source=inv_src, status__in=ACTIVE_STATES).exists():
-                    logger.debug('Skipping SCM inventory update for `{}` because ' 'another update is already active.'.format(inv_src.name))
-                    continue
-
-                if settings.IS_K8S:
-                    instance_group = InventoryUpdate(inventory_source=inv_src).preferred_instance_groups[0]
-                else:
-                    instance_group = project_update.instance_group
-
-                local_inv_update = inv_src.create_inventory_update(
-                    _eager_fields=dict(
-                        launch_type='scm',
-                        status='running',
-                        instance_group=instance_group,
-                        execution_node=project_update.execution_node,
-                        controller_node=project_update.execution_node,
-                        source_project_update=project_update,
-                        celery_task_id=project_update.celery_task_id,
-                    )
-                )
-                local_inv_update.log_lifecycle("controller_node_chosen")
-                local_inv_update.log_lifecycle("execution_node_chosen")
-            try:
-                create_partition(local_inv_update.event_class._meta.db_table, start=local_inv_update.created)
-                inv_update_class().run(local_inv_update.id)
-            except Exception:
-                logger.exception('{} Unhandled exception updating dependent SCM inventory sources.'.format(project_update.log_format))
-
-            try:
-                project_update.refresh_from_db()
-            except ProjectUpdate.DoesNotExist:
-                logger.warning('Project update deleted during updates of dependent SCM inventory sources.')
-                break
-            try:
-                local_inv_update.refresh_from_db()
-            except InventoryUpdate.DoesNotExist:
-                logger.warning('%s Dependent inventory update deleted during execution.', project_update.log_format)
-                continue
-            if project_update.cancel_flag:
-                logger.info('Project update {} was canceled while updating dependent inventories.'.format(project_update.log_format))
-                break
-            if local_inv_update.cancel_flag:
-                logger.info('Continuing to process project dependencies after {} was canceled'.format(local_inv_update.log_format))
-            if local_inv_update.status == 'successful':
-                inv_src.scm_last_revision = scm_revision
-                inv_src.save(update_fields=['scm_last_revision'])
-
     def release_lock(self, instance):
         try:
             fcntl.lockf(self.lock_fd, fcntl.LOCK_UN)
@@ -1435,12 +1375,6 @@ class RunProjectUpdate(BaseTask):
             p.inventory_files = p.inventories
             p.save(update_fields=['scm_revision', 'playbook_files', 'inventory_files'])
 
-        # Update any inventories that depend on this project
-        dependent_inventory_sources = p.scm_inventory_sources.filter(update_on_project_update=True)
-        if len(dependent_inventory_sources) > 0:
-            if status == 'successful' and instance.launch_type != 'sync':
-                self._update_dependent_inventories(instance, dependent_inventory_sources)
-
     def build_execution_environment_params(self, instance, private_data_dir):
         if settings.IS_K8S:
             return {}
@@ -1620,9 +1554,7 @@ class RunInventoryUpdate(BaseTask):
         source_project = None
         if inventory_update.inventory_source:
             source_project = inventory_update.inventory_source.source_project
-        if (
-            inventory_update.source == 'scm' and inventory_update.launch_type != 'scm' and source_project and source_project.scm_type
-        ):  # never ever update manual projects
+        if inventory_update.source == 'scm' and source_project and source_project.scm_type:  # never ever update manual projects
 
             # Check if the content cache exists, so that we do not unnecessarily re-download roles
             sync_needs = ['update_{}'.format(source_project.scm_type)]
@@ -1655,8 +1587,6 @@ class RunInventoryUpdate(BaseTask):
                 sync_task = project_update_task(job_private_data_dir=private_data_dir)
                 sync_task.run(local_project_sync.id)
                 local_project_sync.refresh_from_db()
-                inventory_update.inventory_source.scm_last_revision = local_project_sync.scm_revision
-                inventory_update.inventory_source.save(update_fields=['scm_last_revision'])
             except Exception:
                 inventory_update = self.update_model(
                     inventory_update.pk,
@@ -1667,9 +1597,6 @@ class RunInventoryUpdate(BaseTask):
                     ),
                 )
                 raise
-        elif inventory_update.source == 'scm' and inventory_update.launch_type == 'scm' and source_project:
-            # This follows update, not sync, so make copy here
-            RunProjectUpdate.make_local_copy(source_project, private_data_dir)
 
     def post_run_hook(self, inventory_update, status):
         super(RunInventoryUpdate, self).post_run_hook(inventory_update, status)
diff --git a/awx/main/tests/functional/api/test_deprecated_credential_assignment.py b/awx/main/tests/functional/api/test_deprecated_credential_assignment.py
index e8b4c2070e..266218c0cb 100644
--- a/awx/main/tests/functional/api/test_deprecated_credential_assignment.py
+++ b/awx/main/tests/functional/api/test_deprecated_credential_assignment.py
@@ -9,9 +9,7 @@ from awx.api.versioning import reverse
 @pytest.fixture
 def ec2_source(inventory, project):
     with mock.patch('awx.main.models.unified_jobs.UnifiedJobTemplate.update'):
-        return inventory.inventory_sources.create(
-            name='some_source', update_on_project_update=True, source='ec2', source_project=project, scm_last_revision=project.scm_revision
-        )
+        return inventory.inventory_sources.create(name='some_source', source='ec2', source_project=project)
 
 
 @pytest.fixture
diff --git a/awx/main/tests/functional/api/test_inventory.py b/awx/main/tests/functional/api/test_inventory.py
index 5bb80bdbbd..80357a22f9 100644
--- a/awx/main/tests/functional/api/test_inventory.py
+++ b/awx/main/tests/functional/api/test_inventory.py
@@ -13,9 +13,7 @@ from awx.main.models import InventorySource, Inventory, ActivityStream
 @pytest.fixture
 def scm_inventory(inventory, project):
     with mock.patch('awx.main.models.unified_jobs.UnifiedJobTemplate.update'):
-        inventory.inventory_sources.create(
-            name='foobar', update_on_project_update=True, source='scm', source_project=project, scm_last_revision=project.scm_revision
-        )
+        inventory.inventory_sources.create(name='foobar', source='scm', source_project=project)
     return inventory
 
 
@@ -23,9 +21,7 @@ def scm_inventory(inventory, project):
 def factory_scm_inventory(inventory, project):
     def fn(**kwargs):
         with mock.patch('awx.main.models.unified_jobs.UnifiedJobTemplate.update'):
-            return inventory.inventory_sources.create(
-                source_project=project, overwrite_vars=True, source='scm', scm_last_revision=project.scm_revision, **kwargs
-            )
+            return inventory.inventory_sources.create(source_project=project, overwrite_vars=True, source='scm', **kwargs)
 
     return fn
 
@@ -544,15 +540,12 @@ class TestControlledBySCM:
     def test_safe_method_works(self, get, options, scm_inventory, admin_user):
         get(scm_inventory.get_absolute_url(), admin_user, expect=200)
         options(scm_inventory.get_absolute_url(), admin_user, expect=200)
-        assert InventorySource.objects.get(inventory=scm_inventory.pk).scm_last_revision != ''
 
     def test_vars_edit_reset(self, patch, scm_inventory, admin_user):
         patch(scm_inventory.get_absolute_url(), {'variables': 'hello: world'}, admin_user, expect=200)
-        assert InventorySource.objects.get(inventory=scm_inventory.pk).scm_last_revision == ''
 
     def test_name_edit_allowed(self, patch, scm_inventory, admin_user):
         patch(scm_inventory.get_absolute_url(), {'variables': '---', 'name': 'newname'}, admin_user, expect=200)
-        assert InventorySource.objects.get(inventory=scm_inventory.pk).scm_last_revision != ''
 
     def test_host_associations_reset(self, post, scm_inventory, admin_user):
         inv_src = scm_inventory.inventory_sources.first()
@@ -560,14 +553,12 @@ class TestControlledBySCM:
         g = inv_src.groups.create(name='fooland', inventory=scm_inventory)
         post(reverse('api:host_groups_list', kwargs={'pk': h.id}), {'id': g.id}, admin_user, expect=204)
         post(reverse('api:group_hosts_list', kwargs={'pk': g.id}), {'id': h.id}, admin_user, expect=204)
-        assert InventorySource.objects.get(inventory=scm_inventory.pk).scm_last_revision == ''
 
     def test_group_group_associations_reset(self, post, scm_inventory, admin_user):
         inv_src = scm_inventory.inventory_sources.first()
         g1 = inv_src.groups.create(name='barland', inventory=scm_inventory)
         g2 = inv_src.groups.create(name='fooland', inventory=scm_inventory)
         post(reverse('api:group_children_list', kwargs={'pk': g1.id}), {'id': g2.id}, admin_user, expect=204)
-        assert InventorySource.objects.get(inventory=scm_inventory.pk).scm_last_revision == ''
 
     def test_host_group_delete_reset(self, delete, scm_inventory, admin_user):
         inv_src = scm_inventory.inventory_sources.first()
@@ -575,7 +566,6 @@ class TestControlledBySCM:
         g = inv_src.groups.create(name='fooland', inventory=scm_inventory)
         delete(h.get_absolute_url(), admin_user, expect=204)
         delete(g.get_absolute_url(), admin_user, expect=204)
-        assert InventorySource.objects.get(inventory=scm_inventory.pk).scm_last_revision == ''
 
     def test_remove_scm_inv_src(self, delete, scm_inventory, admin_user):
         inv_src = scm_inventory.inventory_sources.first()
@@ -588,7 +578,6 @@ class TestControlledBySCM:
             {
                 'name': 'new inv src',
                 'source_project': project.pk,
-                'update_on_project_update': False,
                 'source': 'scm',
                 'overwrite_vars': True,
                 'source_vars': 'plugin: a.b.c',
@@ -597,27 +586,6 @@ class TestControlledBySCM:
             expect=201,
         )
 
-    def test_adding_inv_src_prohibited(self, post, scm_inventory, project, admin_user):
-        post(
-            reverse('api:inventory_inventory_sources_list', kwargs={'pk': scm_inventory.id}),
-            {'name': 'new inv src', 'source_project': project.pk, 'update_on_project_update': True, 'source': 'scm', 'overwrite_vars': True},
-            admin_user,
-            expect=400,
-        )
-
-    def test_two_update_on_project_update_inv_src_prohibited(self, patch, scm_inventory, factory_scm_inventory, project, admin_user):
-        scm_inventory2 = factory_scm_inventory(name="scm_inventory2")
-        res = patch(
-            reverse('api:inventory_source_detail', kwargs={'pk': scm_inventory2.id}),
-            {
-                'update_on_project_update': True,
-            },
-            admin_user,
-            expect=400,
-        )
-        content = json.loads(res.content)
-        assert content['update_on_project_update'] == ["More than one SCM-based inventory source with update on project update " "per-inventory not allowed."]
-
     def test_adding_inv_src_without_proj_access_prohibited(self, post, project, inventory, rando):
         inventory.admin_role.members.add(rando)
         post(
diff --git a/awx/main/tests/functional/conftest.py b/awx/main/tests/functional/conftest.py
index ea18b491e6..2e3563a2b6 100644
--- a/awx/main/tests/functional/conftest.py
+++ b/awx/main/tests/functional/conftest.py
@@ -347,9 +347,7 @@ def scm_inventory_source(inventory, project):
         source_project=project,
         source='scm',
         source_path='inventory_file',
-        update_on_project_update=True,
         inventory=inventory,
-        scm_last_revision=project.scm_revision,
     )
     with mock.patch('awx.main.models.unified_jobs.UnifiedJobTemplate.update'):
         inv_src.save()
diff --git a/awx/main/tests/functional/models/test_inventory.py b/awx/main/tests/functional/models/test_inventory.py
index 6c418e5b16..d246853c83 100644
--- a/awx/main/tests/functional/models/test_inventory.py
+++ b/awx/main/tests/functional/models/test_inventory.py
@@ -3,8 +3,6 @@
 import pytest
 from unittest import mock
 
-from django.core.exceptions import ValidationError
-
 # AWX
 from awx.main.models import Host, Inventory, InventorySource, InventoryUpdate, CredentialType, Credential, Job
 from awx.main.constants import CLOUD_PROVIDERS
@@ -123,19 +121,6 @@ class TestActiveCount:
 
 @pytest.mark.django_db
 class TestSCMUpdateFeatures:
-    def test_automatic_project_update_on_create(self, inventory, project):
-        inv_src = InventorySource(source_project=project, source_path='inventory_file', inventory=inventory, update_on_project_update=True, source='scm')
-        with mock.patch.object(inv_src, 'update') as mck_update:
-            inv_src.save()
-            mck_update.assert_called_once_with()
-
-    def test_reset_scm_revision(self, scm_inventory_source):
-        starting_rev = scm_inventory_source.scm_last_revision
-        assert starting_rev != ''
-        scm_inventory_source.source_path = '/newfolder/newfile.ini'
-        scm_inventory_source.save()
-        assert scm_inventory_source.scm_last_revision == ''
-
     def test_source_location(self, scm_inventory_source):
         # Combines project directory with the inventory file specified
         inventory_update = InventoryUpdate(inventory_source=scm_inventory_source, source_path=scm_inventory_source.source_path)
@@ -167,22 +152,6 @@ class TestRelatedJobs:
         assert job.id in [jerb.id for jerb in group._get_related_jobs()]
 
 
-@pytest.mark.django_db
-class TestSCMClean:
-    def test_clean_update_on_project_update_multiple(self, inventory):
-        inv_src1 = InventorySource(inventory=inventory, update_on_project_update=True, source='scm')
-        inv_src1.clean_update_on_project_update()
-        inv_src1.save()
-
-        inv_src1.source_vars = '---\nhello: world'
-        inv_src1.clean_update_on_project_update()
-
-        inv_src2 = InventorySource(inventory=inventory, update_on_project_update=True, source='scm')
-
-        with pytest.raises(ValidationError):
-            inv_src2.clean_update_on_project_update()
-
-
 @pytest.mark.django_db
 class TestInventorySourceInjectors:
     def test_extra_credentials(self, project, credential):
diff --git a/awx/main/tests/functional/test_tasks.py b/awx/main/tests/functional/test_tasks.py
index cb66a07ba3..0e85dc389d 100644
--- a/awx/main/tests/functional/test_tasks.py
+++ b/awx/main/tests/functional/test_tasks.py
@@ -4,9 +4,8 @@ import os
 import tempfile
 import shutil
 
-from awx.main.tasks.jobs import RunProjectUpdate, RunInventoryUpdate
 from awx.main.tasks.system import execution_node_health_check, _cleanup_images_and_files
-from awx.main.models import ProjectUpdate, InventoryUpdate, InventorySource, Instance, Job
+from awx.main.models import Instance, Job
 
 
 @pytest.fixture
@@ -27,63 +26,6 @@ def test_no_worker_info_on_AWX_nodes(node_type):
         execution_node_health_check(hostname)
 
 
-@pytest.mark.django_db
-class TestDependentInventoryUpdate:
-    def test_dependent_inventory_updates_is_called(self, scm_inventory_source, scm_revision_file, mock_me):
-        task = RunProjectUpdate()
-        task.revision_path = scm_revision_file
-        proj_update = scm_inventory_source.source_project.create_project_update()
-        with mock.patch.object(RunProjectUpdate, '_update_dependent_inventories') as inv_update_mck:
-            with mock.patch.object(RunProjectUpdate, 'release_lock'):
-                task.post_run_hook(proj_update, 'successful')
-                inv_update_mck.assert_called_once_with(proj_update, mock.ANY)
-
-    def test_no_unwanted_dependent_inventory_updates(self, project, scm_revision_file, mock_me):
-        task = RunProjectUpdate()
-        task.revision_path = scm_revision_file
-        proj_update = project.create_project_update()
-        with mock.patch.object(RunProjectUpdate, '_update_dependent_inventories') as inv_update_mck:
-            with mock.patch.object(RunProjectUpdate, 'release_lock'):
-                task.post_run_hook(proj_update, 'successful')
-                assert not inv_update_mck.called
-
-    def test_dependent_inventory_updates(self, scm_inventory_source, default_instance_group, mock_me):
-        task = RunProjectUpdate()
-        scm_inventory_source.scm_last_revision = ''
-        proj_update = ProjectUpdate.objects.create(project=scm_inventory_source.source_project)
-        with mock.patch.object(RunInventoryUpdate, 'run') as iu_run_mock:
-            with mock.patch('awx.main.tasks.jobs.create_partition'):
-                task._update_dependent_inventories(proj_update, [scm_inventory_source])
-                assert InventoryUpdate.objects.count() == 1
-                inv_update = InventoryUpdate.objects.first()
-                iu_run_mock.assert_called_once_with(inv_update.id)
-                assert inv_update.source_project_update_id == proj_update.pk
-
-    def test_dependent_inventory_project_cancel(self, project, inventory, default_instance_group, mock_me):
-        """
-        Test that dependent inventory updates exhibit good behavior on cancel
-        of the source project update
-        """
-        task = RunProjectUpdate()
-        proj_update = ProjectUpdate.objects.create(project=project)
-
-        kwargs = dict(source_project=project, source='scm', source_path='inventory_file', update_on_project_update=True, inventory=inventory)
-
-        is1 = InventorySource.objects.create(name="test-scm-inv", **kwargs)
-        is2 = InventorySource.objects.create(name="test-scm-inv2", **kwargs)
-
-        def user_cancels_project(pk):
-            ProjectUpdate.objects.all().update(cancel_flag=True)
-
-        with mock.patch.object(RunInventoryUpdate, 'run') as iu_run_mock:
-            with mock.patch('awx.main.tasks.jobs.create_partition'):
-                iu_run_mock.side_effect = user_cancels_project
-                task._update_dependent_inventories(proj_update, [is1, is2])
-                # Verify that it bails after 1st update, detecting a cancel
-                assert is2.inventory_updates.count() == 0
-                iu_run_mock.assert_called_once()
-
-
 @pytest.fixture
 def mock_job_folder(request):
     pdd_path = tempfile.mkdtemp(prefix='awx_123_')
diff --git a/awx/main/tests/unit/api/test_views.py b/awx/main/tests/unit/api/test_views.py
index 8e7b7a73dc..7f69c816e7 100644
--- a/awx/main/tests/unit/api/test_views.py
+++ b/awx/main/tests/unit/api/test_views.py
@@ -69,21 +69,21 @@ class TestJobTemplateLabelList:
 
 class TestInventoryInventorySourcesUpdate:
     @pytest.mark.parametrize(
-        "can_update, can_access, is_source, is_up_on_proj, expected",
+        "can_update, can_access, is_source, expected",
         [
-            (True, True, "ec2", False, [{'status': 'started', 'inventory_update': 1, 'inventory_source': 1}]),
-            (False, True, "gce", False, [{'status': 'Could not start because `can_update` returned False', 'inventory_source': 1}]),
-            (True, False, "scm", True, [{'status': 'started', 'inventory_update': 1, 'inventory_source': 1}]),
+            (True, True, "ec2", [{'status': 'started', 'inventory_update': 1, 'inventory_source': 1}]),
+            (False, True, "gce", [{'status': 'Could not start because `can_update` returned False', 'inventory_source': 1}]),
+            (True, False, "scm", [{'status': 'started', 'inventory_update': 1, 'inventory_source': 1}]),
         ],
     )
-    def test_post(self, mocker, can_update, can_access, is_source, is_up_on_proj, expected):
+    def test_post(self, mocker, can_update, can_access, is_source, expected):
         class InventoryUpdate:
             id = 1
 
         class Project:
             name = 'project'
 
-        InventorySource = namedtuple('InventorySource', ['source', 'update_on_project_update', 'pk', 'can_update', 'update', 'source_project'])
+        InventorySource = namedtuple('InventorySource', ['source', 'pk', 'can_update', 'update', 'source_project'])
 
         class InventorySources(object):
             def all(self):
@@ -92,7 +92,6 @@ class TestInventoryInventorySourcesUpdate:
                         pk=1,
                         source=is_source,
                         source_project=Project,
-                        update_on_project_update=is_up_on_proj,
                         can_update=can_update,
                         update=lambda: InventoryUpdate,
                     )
diff --git a/awx/main/tests/unit/models/test_inventory.py b/awx/main/tests/unit/models/test_inventory.py
index 34a8000665..92d041b8e3 100644
--- a/awx/main/tests/unit/models/test_inventory.py
+++ b/awx/main/tests/unit/models/test_inventory.py
@@ -1,28 +1,13 @@
 import pytest
-from unittest import mock
 
 from django.core.exceptions import ValidationError
 
 from awx.main.models import (
-    UnifiedJob,
     InventoryUpdate,
     InventorySource,
 )
 
 
-def test_cancel(mocker):
-    with mock.patch.object(UnifiedJob, 'cancel', return_value=True) as parent_cancel:
-        iu = InventoryUpdate()
-
-        iu.save = mocker.MagicMock()
-        build_job_explanation_mock = mocker.MagicMock()
-        iu._build_job_explanation = mocker.MagicMock(return_value=build_job_explanation_mock)
-
-        iu.cancel()
-
-        parent_cancel.assert_called_with(is_chain=False, job_explanation=None)
-
-
 def test__build_job_explanation():
     iu = InventoryUpdate(id=3, name='I_am_an_Inventory_Update')
 
@@ -53,9 +38,3 @@ class TestControlledBySCM:
 
         with pytest.raises(ValidationError):
             inv_src.clean_source_path()
-
-    def test_clean_update_on_launch_update_on_project_update(self):
-        inv_src = InventorySource(update_on_project_update=True, update_on_launch=True, source='scm')
-
-        with pytest.raises(ValidationError):
-            inv_src.clean_update_on_launch()
diff --git a/awx_collection/plugins/modules/inventory_source.py b/awx_collection/plugins/modules/inventory_source.py
index 1072ff1314..f3000ee9ec 100644
--- a/awx_collection/plugins/modules/inventory_source.py
+++ b/awx_collection/plugins/modules/inventory_source.py
@@ -105,9 +105,6 @@ options:
       description:
         - Project to use as source with scm option
       type: str
-    update_on_project_update:
-      description: Update this source when the related project updates if source is C(scm)
-      type: bool
     state:
       description:
         - Desired state of the resource.
@@ -181,7 +178,6 @@ def main():
         update_on_launch=dict(type='bool'),
         update_cache_timeout=dict(type='int'),
         source_project=dict(),
-        update_on_project_update=dict(type='bool'),
         notification_templates_started=dict(type="list", elements='str'),
         notification_templates_success=dict(type="list", elements='str'),
         notification_templates_error=dict(type="list", elements='str'),
@@ -273,7 +269,6 @@ def main():
         'verbosity',
         'update_on_launch',
         'update_cache_timeout',
-        'update_on_project_update',
         'enabled_var',
         'enabled_value',
         'host_filter',
diff --git a/docs/inventory/scm_inventory.md b/docs/inventory/scm_inventory.md
index bb48e01a80..f3342a1aa5 100644
--- a/docs/inventory/scm_inventory.md
+++ b/docs/inventory/scm_inventory.md
@@ -17,21 +17,6 @@ Additionally:
 
  - `source_vars` - if these are set on a "file" type inventory source
    then they will be passed to the environment vars when running
- - `update_on_project_update` - if set, a project update of the source
-   project will automatically update this inventory source as a side effect
-
-If `update_on_project_update` is not set, then they can manually update
-just the inventory source with a POST to its update endpoint,
-`/inventory_sources/N/update/`.
-
-If `update_on_project_update` is set, the POST to the inventory source's
-update endpoint will trigger an update of the source project, which may,
-in turn, trigger an update of the inventory source.
-Also, with this flag set, an update _of the project_ is
-scheduled immediately after creation of the inventory source.
-Also, if this flag is set, no inventory updates will be triggered
-_unless the SCM revision of the project changes_.
-
 
 ### RBAC
 
@@ -52,17 +37,6 @@ This listing should be refreshed to the latest SCM info on a project update.
 If no inventory sources use a project as an SCM inventory source, then
 the inventory listing may not be refreshed on update.
 
-
-### Inventory Source Restriction
-
-Since automatic inventory updates (triggered by a project update) do not
-go through the task system, typical protection against conflicting updates
-is not available. To avoid problems, only one inventory source is allowed for
-inventories that use this feature. That means that if an inventory source
-has `source=scm` and `update_on_project_update=true`, it can be the only
-inventory source for its inventory.
-
-
 ## Supported File Syntax
 
 > Any Inventory Ansible supports should be supported by this feature.