diff --git a/cyclonedx/model/bom_ref.py b/cyclonedx/model/bom_ref.py
new file mode 100644
index 00000000..69bd9f31
--- /dev/null
+++ b/cyclonedx/model/bom_ref.py
@@ -0,0 +1,53 @@
+# encoding: utf-8
+
+# This file is part of CycloneDX Python Lib
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (c) OWASP Foundation. All Rights Reserved.
+from typing import Optional
+from uuid import uuid4
+
+
+class BomRef:
+    """
+    An identifier that can be used to reference objects elsewhere in the BOM.
+
+    This copies a similar pattern used in the CycloneDX Python Library.
+
+    .. note::
+        See https://github.com/CycloneDX/cyclonedx-php-library/blob/master/docs/dev/decisions/BomDependencyDataModel.md
+    """
+
+    def __init__(self, value: Optional[str] = None) -> None:
+        self.value = value or str(uuid4())
+
+    @property
+    def value(self) -> str:
+        return self._value
+
+    @value.setter
+    def value(self, value: str) -> None:
+        self._value = value
+
+    def __eq__(self, other: object) -> bool:
+        if isinstance(other, BomRef):
+            return hash(other) == hash(self)
+        return False
+
+    def __hash__(self) -> int:
+        return hash(self.value)
+
+    def __repr__(self) -> str:
+        return self.value
diff --git a/cyclonedx/model/component.py b/cyclonedx/model/component.py
index c8151746..8d07db45 100644
--- a/cyclonedx/model/component.py
+++ b/cyclonedx/model/component.py
@@ -20,13 +20,13 @@
 from enum import Enum
 from os.path import exists
 from typing import Iterable, Optional, Set
-from uuid import uuid4
 
 # See https://github.com/package-url/packageurl-python/issues/65
 from packageurl import PackageURL  # type: ignore
 
 from . import AttachedText, Copyright, ExternalReference, HashAlgorithm, HashType, IdentifiableAction, LicenseChoice, \
     OrganizationalEntity, Property, sha1sum, XsUri
+from .bom_ref import BomRef
 from .issue import IssueType
 from .release_note import ReleaseNotes
 from .vulnerability import Vulnerability
@@ -692,7 +692,7 @@ def __init__(self, *, name: str, component_type: ComponentType = ComponentType.L
                  ) -> None:
         self.type = component_type
         self.mime_type = mime_type
-        self.bom_ref = bom_ref or str(uuid4())
+        self._bom_ref = BomRef(value=bom_ref)
         self.supplier = supplier
         self.author = author
         self.publisher = publisher
@@ -766,7 +766,7 @@ def mime_type(self, mime_type: Optional[str]) -> None:
         self._mime_type = mime_type
 
     @property
-    def bom_ref(self) -> str:
+    def bom_ref(self) -> BomRef:
         """
         An optional identifier which can be used to reference the component elsewhere in the BOM. Every bom-ref MUST be
         unique within the BOM.
@@ -774,14 +774,10 @@ def bom_ref(self) -> str:
         If a value was not provided in the constructor, a UUIDv4 will have been assigned.
 
         Returns:
-            `str` as a unique identifiers for this Component
+            `BomRef`
         """
         return self._bom_ref
 
-    @bom_ref.setter
-    def bom_ref(self, bom_ref: str) -> None:
-        self._bom_ref = bom_ref
-
     @property
     def supplier(self) -> Optional[OrganizationalEntity]:
         """
diff --git a/cyclonedx/model/service.py b/cyclonedx/model/service.py
index e695ea9c..5f387973 100644
--- a/cyclonedx/model/service.py
+++ b/cyclonedx/model/service.py
@@ -15,9 +15,9 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (c) OWASP Foundation. All Rights Reserved.
 from typing import Iterable, Optional, Set
-from uuid import uuid4
 
 from . import ExternalReference, DataClassification, LicenseChoice, OrganizationalEntity, Property, XsUri
+from .bom_ref import BomRef
 from .release_note import ReleaseNotes
 
 """
@@ -46,7 +46,7 @@ def __init__(self, *, name: str, bom_ref: Optional[str] = None, provider: Option
                  services: Optional[Iterable['Service']] = None,
                  release_notes: Optional[ReleaseNotes] = None,
                  ) -> None:
-        self.bom_ref = bom_ref or str(uuid4())
+        self._bom_ref = BomRef(value=bom_ref)
         self.provider = provider
         self.group = group
         self.name = name
@@ -63,7 +63,7 @@ def __init__(self, *, name: str, bom_ref: Optional[str] = None, provider: Option
         self.properties = set(properties or [])
 
     @property
-    def bom_ref(self) -> Optional[str]:
+    def bom_ref(self) -> BomRef:
         """
         An optional identifier which can be used to reference the service elsewhere in the BOM. Uniqueness is enforced
         within all elements and children of the root-level bom element.
@@ -71,14 +71,10 @@ def bom_ref(self) -> Optional[str]:
         If a value was not provided in the constructor, a UUIDv4 will have been assigned.
 
         Returns:
-           `str` unique identifier for this Service
+           `BomRef` unique identifier for this Service
         """
         return self._bom_ref
 
-    @bom_ref.setter
-    def bom_ref(self, bom_ref: Optional[str]) -> None:
-        self._bom_ref = bom_ref
-
     @property
     def provider(self) -> Optional[OrganizationalEntity]:
         """
diff --git a/cyclonedx/model/vulnerability.py b/cyclonedx/model/vulnerability.py
index 0eed7f22..96e64c6c 100644
--- a/cyclonedx/model/vulnerability.py
+++ b/cyclonedx/model/vulnerability.py
@@ -22,9 +22,9 @@
 from decimal import Decimal
 from enum import Enum
 from typing import Iterable, Optional, Set, Tuple, Union
-from uuid import uuid4
 
 from . import OrganizationalContact, OrganizationalEntity, Tool, XsUri
+from .bom_ref import BomRef
 from .impact_analysis import ImpactAnalysisAffectedStatus, ImpactAnalysisJustification, ImpactAnalysisResponse, \
     ImpactAnalysisState
 from ..exception.model import MutuallyExclusivePropertiesException, NoPropertiesProvidedException
@@ -745,7 +745,7 @@ def __init__(self, *, bom_ref: Optional[str] = None, id: Optional[str] = None,
                  # Deprecated Parameters kept for backwards compatibility
                  source_name: Optional[str] = None, source_url: Optional[str] = None,
                  recommendations: Optional[Iterable[str]] = None) -> None:
-        self.bom_ref = bom_ref or str(uuid4())
+        self._bom_ref = BomRef(value=bom_ref)
         self.id = id
         self.source = source
         self.references = set(references or [])
@@ -774,21 +774,17 @@ def __init__(self, *, bom_ref: Optional[str] = None, id: Optional[str] = None,
                 self.recommendation = next(iter(recommendations))
 
     @property
-    def bom_ref(self) -> Optional[str]:
+    def bom_ref(self) -> BomRef:
         """
         Get the unique reference for this Vulnerability in this BOM.
 
         If a value was not provided in the constructor, a UUIDv4 will have been assigned.
 
         Returns:
-           `str` if set else `None`
+           `BomRef`
         """
         return self._bom_ref
 
-    @bom_ref.setter
-    def bom_ref(self, bom_ref: Optional[str]) -> None:
-        self._bom_ref = bom_ref
-
     @property
     def id(self) -> Optional[str]:
         """
diff --git a/cyclonedx/output/serializer/json.py b/cyclonedx/output/serializer/json.py
index 858e536b..3598c8ec 100644
--- a/cyclonedx/output/serializer/json.py
+++ b/cyclonedx/output/serializer/json.py
@@ -16,7 +16,6 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # Copyright (c) OWASP Foundation. All Rights Reserved.
-
 from datetime import datetime
 from decimal import Decimal
 from enum import Enum
@@ -28,8 +27,9 @@
 # See https://github.com/package-url/packageurl-python/issues/65
 from packageurl import PackageURL  # type: ignore
 
-from cyclonedx.model import XsUri
-from cyclonedx.model.component import Component
+from ...model import XsUri
+from ...model.bom_ref import BomRef
+from ...model.component import Component
 
 HYPHENATED_ATTRIBUTES = [
     'bom_ref', 'mime_type', 'x_trust_boundary'
@@ -40,6 +40,10 @@
 class CycloneDxJSONEncoder(JSONEncoder):
 
     def default(self, o: Any) -> Any:
+        # BomRef
+        if isinstance(o, BomRef):
+            return str(o)
+
         # datetime
         if isinstance(o, datetime):
             return o.isoformat()
diff --git a/cyclonedx/output/xml.py b/cyclonedx/output/xml.py
index acc5a5fb..4af463bd 100644
--- a/cyclonedx/output/xml.py
+++ b/cyclonedx/output/xml.py
@@ -27,6 +27,7 @@
 from ..model import AttachedText, ExternalReference, HashType, IdentifiableAction, LicenseChoice, \
     OrganizationalEntity, OrganizationalContact, Property, Tool
 from ..model.bom import Bom
+from ..model.bom_ref import BomRef
 from ..model.component import Component, Patch
 from ..model.release_note import ReleaseNotes
 from ..model.service import Service
@@ -174,7 +175,7 @@ def _add_metadata_element(self) -> None:
     def _add_component_element(self, component: Component) -> ElementTree.Element:
         element_attributes = {'type': component.type.value}
         if self.component_supports_bom_ref_attribute() and component.bom_ref:
-            element_attributes['bom-ref'] = component.bom_ref
+            element_attributes['bom-ref'] = str(component.bom_ref)
         if self.component_supports_mime_type_attribute() and component.mime_type:
             element_attributes['mime-type'] = component.mime_type
 
@@ -450,7 +451,7 @@ def _add_properties_element(properties: Set[Property], parent_element: ElementTr
     def _add_service_element(self, service: Service) -> ElementTree.Element:
         element_attributes = {}
         if service.bom_ref:
-            element_attributes['bom-ref'] = service.bom_ref
+            element_attributes['bom-ref'] = str(service.bom_ref)
 
         service_element = ElementTree.Element('service', element_attributes)
 
@@ -525,7 +526,7 @@ def _add_service_element(self, service: Service) -> ElementTree.Element:
     def _get_vulnerability_as_xml_element_post_1_4(self, vulnerability: Vulnerability) -> ElementTree.Element:
         vulnerability_element = ElementTree.Element(
             'vulnerability',
-            {'bom-ref': vulnerability.bom_ref} if vulnerability.bom_ref else {}
+            {'bom-ref': str(vulnerability.bom_ref)} if vulnerability.bom_ref else {}
         )
 
         # id
@@ -654,10 +655,10 @@ def _get_vulnerability_as_xml_element_post_1_4(self, vulnerability: Vulnerabilit
         return vulnerability_element
 
     @staticmethod
-    def _get_vulnerability_as_xml_element_pre_1_3(bom_ref: str,
+    def _get_vulnerability_as_xml_element_pre_1_3(bom_ref: BomRef,
                                                   vulnerability: Vulnerability) -> ElementTree.Element:
         vulnerability_element = ElementTree.Element('v:vulnerability', {
-            'ref': bom_ref
+            'ref': str(bom_ref)
         })
 
         # id
diff --git a/tests/data.py b/tests/data.py
index cd0571fc..2e5fc805 100644
--- a/tests/data.py
+++ b/tests/data.py
@@ -45,6 +45,10 @@
 MOCK_UUID_5 = 'bb5911d6-1a1d-41c9-b6e0-46e848d16655'
 MOCK_UUID_6 = 'df70b5f1-8f53-47a4-be48-669ae78795e6'
 
+TEST_UUIDS = [
+    MOCK_UUID_1, MOCK_UUID_2, MOCK_UUID_3, MOCK_UUID_4, MOCK_UUID_5, MOCK_UUID_6
+]
+
 
 def get_bom_with_component_setuptools_basic() -> Bom:
     return Bom(components=[get_component_setuptools_simple()])
diff --git a/tests/fixtures/json/1.2/bom_services_complex.json b/tests/fixtures/json/1.2/bom_services_complex.json
index cbf93031..8cc31cd2 100644
--- a/tests/fixtures/json/1.2/bom_services_complex.json
+++ b/tests/fixtures/json/1.2/bom_services_complex.json
@@ -15,7 +15,7 @@
     ],
     "component": {
       "type": "library",
-      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
+      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
       "name": "cyclonedx-python-lib",
       "version": "1.0.0"
     }
@@ -76,7 +76,7 @@
       ]
     },
     {
-      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
+      "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
       "name": "my-second-service"
     }
   ]
diff --git a/tests/fixtures/json/1.2/bom_services_nested.json b/tests/fixtures/json/1.2/bom_services_nested.json
index b1a8a0d2..46de1b3b 100644
--- a/tests/fixtures/json/1.2/bom_services_nested.json
+++ b/tests/fixtures/json/1.2/bom_services_nested.json
@@ -3,7 +3,7 @@
   "bomFormat": "CycloneDX",
   "metadata": {
     "component": {
-      "bom-ref": "bb5911d6-1a1d-41c9-b6e0-46e848d16655",
+      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
       "name": "cyclonedx-python-lib",
       "type": "library",
       "version": "1.0.0"
@@ -72,7 +72,7 @@
       },
       "services": [
         {
-          "bom-ref": "df70b5f1-8f53-47a4-be48-669ae78795e6",
+          "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
           "name": "first-nested-service"
         },
         {
@@ -105,11 +105,11 @@
       "x-trust-boundary": true
     },
     {
-      "bom-ref": "df70b5f1-8f53-47a4-be48-669ae78795e6",
+      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
       "name": "my-second-service",
       "services": [
         {
-          "bom-ref": "df70b5f1-8f53-47a4-be48-669ae78795e6",
+          "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
           "group": "what-group",
           "name": "yet-another-nested-service",
           "provider": {
diff --git a/tests/fixtures/json/1.2/bom_services_simple.json b/tests/fixtures/json/1.2/bom_services_simple.json
index 696cafe4..db950b0e 100644
--- a/tests/fixtures/json/1.2/bom_services_simple.json
+++ b/tests/fixtures/json/1.2/bom_services_simple.json
@@ -15,18 +15,18 @@
     ],
     "component": {
       "type": "library",
-      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
+      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
       "name": "cyclonedx-python-lib",
       "version": "1.0.0"
     }
   },
   "services": [
     {
-      "bom-ref": "bb5911d6-1a1d-41c9-b6e0-46e848d16655",
+      "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
       "name": "my-first-service"
     },
     {
-      "bom-ref": "bb5911d6-1a1d-41c9-b6e0-46e848d16655",
+      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
       "name": "my-second-service"
     }
   ]
diff --git a/tests/fixtures/json/1.3/bom_services_complex.json b/tests/fixtures/json/1.3/bom_services_complex.json
index 24d0ca06..64460386 100644
--- a/tests/fixtures/json/1.3/bom_services_complex.json
+++ b/tests/fixtures/json/1.3/bom_services_complex.json
@@ -15,7 +15,7 @@
     ],
     "component": {
       "type": "library",
-      "bom-ref": "bb5911d6-1a1d-41c9-b6e0-46e848d16655",
+      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
       "name": "cyclonedx-python-lib",
       "version": "1.0.0"
     }
@@ -86,7 +86,7 @@
       ]
     },
     {
-      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
+      "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
       "name": "my-second-service"
     }
   ]
diff --git a/tests/fixtures/json/1.3/bom_services_nested.json b/tests/fixtures/json/1.3/bom_services_nested.json
index 23c0bd1d..216e52e0 100644
--- a/tests/fixtures/json/1.3/bom_services_nested.json
+++ b/tests/fixtures/json/1.3/bom_services_nested.json
@@ -3,7 +3,7 @@
   "bomFormat": "CycloneDX",
   "metadata": {
     "component": {
-      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
+      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
       "name": "cyclonedx-python-lib",
       "type": "library",
       "version": "1.0.0"
@@ -82,7 +82,7 @@
       },
       "services": [
         {
-          "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
+          "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
           "name": "first-nested-service"
         },
         {
@@ -115,11 +115,11 @@
       "x-trust-boundary": true
     },
     {
-      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
+      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
       "name": "my-second-service",
       "services": [
         {
-          "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
+          "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
           "group": "what-group",
           "name": "yet-another-nested-service",
           "provider": {
diff --git a/tests/fixtures/json/1.3/bom_services_simple.json b/tests/fixtures/json/1.3/bom_services_simple.json
index a16b1ed9..31bb109b 100644
--- a/tests/fixtures/json/1.3/bom_services_simple.json
+++ b/tests/fixtures/json/1.3/bom_services_simple.json
@@ -15,18 +15,18 @@
     ],
     "component": {
       "type": "library",
-      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
+      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
       "name": "cyclonedx-python-lib",
       "version": "1.0.0"
     }
   },
   "services": [
     {
-      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
+      "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
       "name": "my-first-service"
     },
     {
-      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
+      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
       "name": "my-second-service"
     }
   ]
diff --git a/tests/fixtures/json/1.4/bom_services_complex.json b/tests/fixtures/json/1.4/bom_services_complex.json
index 78784f48..656a8bbf 100644
--- a/tests/fixtures/json/1.4/bom_services_complex.json
+++ b/tests/fixtures/json/1.4/bom_services_complex.json
@@ -49,7 +49,7 @@
     ],
     "component": {
       "type": "library",
-      "bom-ref": "df70b5f1-8f53-47a4-be48-669ae78795e6",
+      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
       "name": "cyclonedx-python-lib",
       "version": "1.0.0"
     }
@@ -179,7 +179,7 @@
       ]
     },
     {
-      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
+      "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
       "name": "my-second-service"
     }
   ]
diff --git a/tests/fixtures/json/1.4/bom_services_nested.json b/tests/fixtures/json/1.4/bom_services_nested.json
index 93705699..e0e01221 100644
--- a/tests/fixtures/json/1.4/bom_services_nested.json
+++ b/tests/fixtures/json/1.4/bom_services_nested.json
@@ -3,7 +3,7 @@
   "bomFormat": "CycloneDX",
   "metadata": {
     "component": {
-      "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
+      "bom-ref": "cd3e9c95-9d41-49e7-9924-8cf0465ae789",
       "name": "cyclonedx-python-lib",
       "type": "library",
       "version": "1.0.0"
@@ -175,7 +175,7 @@
       },
       "services": [
         {
-          "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
+          "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
           "name": "first-nested-service"
         },
         {
@@ -208,7 +208,7 @@
       "x-trust-boundary": true
     },
     {
-      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
+      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
       "name": "my-second-service",
       "services": [
         {
diff --git a/tests/fixtures/json/1.4/bom_services_simple.json b/tests/fixtures/json/1.4/bom_services_simple.json
index ba87360d..c23f4c63 100644
--- a/tests/fixtures/json/1.4/bom_services_simple.json
+++ b/tests/fixtures/json/1.4/bom_services_simple.json
@@ -49,18 +49,18 @@
     ],
     "component": {
       "type": "library",
-      "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
+      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
       "name": "cyclonedx-python-lib",
       "version": "1.0.0"
     }
   },
   "services": [
     {
-      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
+      "bom-ref": "be2c6502-7e9a-47db-9a66-e34f729810a3",
       "name": "my-first-service"
     },
     {
-      "bom-ref": "0b049d09-64c0-4490-a0f5-c84d9aacf857",
+      "bom-ref": "17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda",
       "name": "my-second-service"
     }
   ]
diff --git a/tests/fixtures/xml/1.2/bom_services_complex.xml b/tests/fixtures/xml/1.2/bom_services_complex.xml
index f330ee7a..1dd5f92d 100644
--- a/tests/fixtures/xml/1.2/bom_services_complex.xml
+++ b/tests/fixtures/xml/1.2/bom_services_complex.xml
@@ -9,7 +9,7 @@
                 <version>VERSION</version>
             </tool>
         </tools>
-        <component bom-ref="cd3e9c95-9d41-49e7-9924-8cf0465ae789" type="library">
+        <component bom-ref="17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda" type="library">
             <name>cyclonedx-python-lib</name>
             <version>1.0.0</version>
         </component>
diff --git a/tests/fixtures/xml/1.2/bom_services_simple.xml b/tests/fixtures/xml/1.2/bom_services_simple.xml
index e02ea1b7..a6cf63c2 100644
--- a/tests/fixtures/xml/1.2/bom_services_simple.xml
+++ b/tests/fixtures/xml/1.2/bom_services_simple.xml
@@ -9,7 +9,7 @@
                 <version>VERSION</version>
             </tool>
         </tools>
-        <component bom-ref="cd3e9c95-9d41-49e7-9924-8cf0465ae789" type="library">
+        <component bom-ref="0b049d09-64c0-4490-a0f5-c84d9aacf857" type="library">
             <name>cyclonedx-python-lib</name>
             <version>1.0.0</version>
         </component>
diff --git a/tests/fixtures/xml/1.3/bom_services_complex.xml b/tests/fixtures/xml/1.3/bom_services_complex.xml
index 56e2cce9..8d2f93c0 100644
--- a/tests/fixtures/xml/1.3/bom_services_complex.xml
+++ b/tests/fixtures/xml/1.3/bom_services_complex.xml
@@ -9,7 +9,7 @@
                 <version>VERSION</version>
             </tool>
         </tools>
-        <component bom-ref="bb5911d6-1a1d-41c9-b6e0-46e848d16655" type="library">
+        <component bom-ref="17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda" type="library">
             <name>cyclonedx-python-lib</name>
             <version>1.0.0</version>
         </component>
diff --git a/tests/fixtures/xml/1.3/bom_services_nested.xml b/tests/fixtures/xml/1.3/bom_services_nested.xml
index df05c422..4ebb2152 100644
--- a/tests/fixtures/xml/1.3/bom_services_nested.xml
+++ b/tests/fixtures/xml/1.3/bom_services_nested.xml
@@ -9,7 +9,7 @@
                 <version>VERSION</version>
             </tool>
         </tools>
-        <component bom-ref="bb5911d6-1a1d-41c9-b6e0-46e848d16655" type="library">
+        <component bom-ref="cd3e9c95-9d41-49e7-9924-8cf0465ae789" type="library">
             <name>cyclonedx-python-lib</name>
             <version>1.0.0</version>
         </component>
diff --git a/tests/fixtures/xml/1.3/bom_services_simple.xml b/tests/fixtures/xml/1.3/bom_services_simple.xml
index c20a7c55..d3feae46 100644
--- a/tests/fixtures/xml/1.3/bom_services_simple.xml
+++ b/tests/fixtures/xml/1.3/bom_services_simple.xml
@@ -9,7 +9,7 @@
                 <version>VERSION</version>
             </tool>
         </tools>
-        <component bom-ref="bb5911d6-1a1d-41c9-b6e0-46e848d16655" type="library">
+        <component bom-ref="0b049d09-64c0-4490-a0f5-c84d9aacf857" type="library">
             <name>cyclonedx-python-lib</name>
             <version>1.0.0</version>
         </component>
diff --git a/tests/fixtures/xml/1.4/bom_services_complex.xml b/tests/fixtures/xml/1.4/bom_services_complex.xml
index e8eb750c..d7187c56 100644
--- a/tests/fixtures/xml/1.4/bom_services_complex.xml
+++ b/tests/fixtures/xml/1.4/bom_services_complex.xml
@@ -35,7 +35,7 @@
                 </externalReferences>
             </tool>
         </tools>
-        <component bom-ref="df70b5f1-8f53-47a4-be48-669ae78795e6" type="library">
+        <component bom-ref="17e3b199-dc0b-42ef-bfdd-1fa81a1e3eda" type="library">
             <name>cyclonedx-python-lib</name>
             <version>1.0.0</version>
         </component>
diff --git a/tests/fixtures/xml/1.4/bom_services_nested.xml b/tests/fixtures/xml/1.4/bom_services_nested.xml
index 0312b4d8..2a3348ef 100644
--- a/tests/fixtures/xml/1.4/bom_services_nested.xml
+++ b/tests/fixtures/xml/1.4/bom_services_nested.xml
@@ -35,7 +35,7 @@
                 </externalReferences>
             </tool>
         </tools>
-        <component bom-ref="df70b5f1-8f53-47a4-be48-669ae78795e6" type="library">
+        <component bom-ref="cd3e9c95-9d41-49e7-9924-8cf0465ae789" type="library">
             <name>cyclonedx-python-lib</name>
             <version>1.0.0</version>
         </component>
diff --git a/tests/fixtures/xml/1.4/bom_services_simple.xml b/tests/fixtures/xml/1.4/bom_services_simple.xml
index 1dea0823..8eb59474 100644
--- a/tests/fixtures/xml/1.4/bom_services_simple.xml
+++ b/tests/fixtures/xml/1.4/bom_services_simple.xml
@@ -35,7 +35,7 @@
                 </externalReferences>
             </tool>
         </tools>
-        <component bom-ref="df70b5f1-8f53-47a4-be48-669ae78795e6" type="library">
+        <component bom-ref="0b049d09-64c0-4490-a0f5-c84d9aacf857" type="library">
             <name>cyclonedx-python-lib</name>
             <version>1.0.0</version>
         </component>
diff --git a/tests/test_model_component.py b/tests/test_model_component.py
index b1c05927..4ae89060 100644
--- a/tests/test_model_component.py
+++ b/tests/test_model_component.py
@@ -54,7 +54,7 @@ def test_not_same(self) -> None:
 
 class TestModelComponent(TestCase):
 
-    @patch('cyclonedx.model.component.uuid4', return_value='6f266d1c-760f-4552-ae3b-41a9b74232fa')
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value='6f266d1c-760f-4552-ae3b-41a9b74232fa')
     def test_empty_basic_component(self, mock_uuid: Mock) -> None:
         c = Component(
             name='test-component', version='1.2.3'
@@ -63,7 +63,7 @@ def test_empty_basic_component(self, mock_uuid: Mock) -> None:
         self.assertEqual(c.name, 'test-component')
         self.assertEqual(c.type, ComponentType.LIBRARY)
         self.assertIsNone(c.mime_type)
-        self.assertEqual(c.bom_ref, '6f266d1c-760f-4552-ae3b-41a9b74232fa')
+        self.assertEqual(str(c.bom_ref), '6f266d1c-760f-4552-ae3b-41a9b74232fa')
         self.assertIsNone(c.supplier)
         self.assertIsNone(c.author)
         self.assertIsNone(c.publisher)
@@ -81,7 +81,7 @@ def test_empty_basic_component(self, mock_uuid: Mock) -> None:
 
         self.assertEqual(len(c.get_vulnerabilities()), 0)
 
-    @patch('cyclonedx.model.component.uuid4', return_value='6f266d1c-760f-4552-ae3b-41a9b74232fa')
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value='6f266d1c-760f-4552-ae3b-41a9b74232fa')
     def test_multiple_basic_components(self, mock_uuid: Mock) -> None:
         c1 = Component(
             name='test-component', version='1.2.3'
diff --git a/tests/test_model_service.py b/tests/test_model_service.py
index 12f589cf..555bcad3 100644
--- a/tests/test_model_service.py
+++ b/tests/test_model_service.py
@@ -24,12 +24,12 @@
 
 class TestModelService(TestCase):
 
-    @patch('cyclonedx.model.service.uuid4', return_value='77d15ab9-5602-4cca-8ed2-59ae579aafd3')
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value='77d15ab9-5602-4cca-8ed2-59ae579aafd3')
     def test_minimal_service(self, mock_uuid: Mock) -> None:
         s = Service(name='my-test-service')
         mock_uuid.assert_called()
         self.assertEqual(s.name, 'my-test-service')
-        self.assertEqual(s.bom_ref, '77d15ab9-5602-4cca-8ed2-59ae579aafd3')
+        self.assertEqual(str(s.bom_ref), '77d15ab9-5602-4cca-8ed2-59ae579aafd3')
         self.assertIsNone(s.provider)
         self.assertIsNone(s.group)
         self.assertIsNone(s.version)
@@ -44,7 +44,7 @@ def test_minimal_service(self, mock_uuid: Mock) -> None:
         self.assertFalse(s.release_notes)
         self.assertFalse(s.properties)
 
-    @patch('cyclonedx.model.service.uuid4', return_value='859ff614-35a7-4d37-803b-d89130cb2577')
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value='859ff614-35a7-4d37-803b-d89130cb2577')
     def test_service_with_services(self, mock_uuid: Mock) -> None:
         parent_service = Service(name='parent-service')
         parent_service.services = [
@@ -53,7 +53,7 @@ def test_service_with_services(self, mock_uuid: Mock) -> None:
         ]
         mock_uuid.assert_called()
         self.assertEqual(parent_service.name, 'parent-service')
-        self.assertEqual(parent_service.bom_ref, '859ff614-35a7-4d37-803b-d89130cb2577')
+        self.assertEqual(str(parent_service.bom_ref), '859ff614-35a7-4d37-803b-d89130cb2577')
         self.assertIsNone(parent_service.provider)
         self.assertIsNone(parent_service.group)
         self.assertIsNone(parent_service.version)
diff --git a/tests/test_model_vulnerability.py b/tests/test_model_vulnerability.py
index 450793cf..0e239b7c 100644
--- a/tests/test_model_vulnerability.py
+++ b/tests/test_model_vulnerability.py
@@ -170,11 +170,11 @@ def test_v_source_get_localised_vector_other_2(self) -> None:
             'SOMETHING_OR_OTHER'
         )
 
-    @patch('cyclonedx.model.vulnerability.uuid4', return_value='0afa65bc-4acd-428b-9e17-8e97b1969745')
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value='0afa65bc-4acd-428b-9e17-8e97b1969745')
     def test_empty_vulnerability(self, mock_uuid: Mock) -> None:
         v = Vulnerability()
         mock_uuid.assert_called()
-        self.assertEqual(v.bom_ref, '0afa65bc-4acd-428b-9e17-8e97b1969745')
+        self.assertEqual(str(v.bom_ref), '0afa65bc-4acd-428b-9e17-8e97b1969745')
         self.assertIsNone(v.id)
         self.assertIsNone(v.source)
         self.assertFalse(v.references)
diff --git a/tests/test_output_json.py b/tests/test_output_json.py
index 109b121d..2f8d6ab0 100644
--- a/tests/test_output_json.py
+++ b/tests/test_output_json.py
@@ -26,9 +26,8 @@
     get_bom_with_services_simple, get_bom_with_component_toml_1, \
     get_bom_with_component_setuptools_no_component_version, \
     get_bom_with_component_setuptools_with_release_notes, get_bom_with_component_setuptools_with_vulnerability, \
-    MOCK_UUID_1, get_bom_just_complete_metadata, MOCK_UUID_2, MOCK_UUID_3, MOCK_UUID_4, MOCK_UUID_5, \
-    get_bom_with_services_complex, MOCK_UUID_6, get_bom_with_nested_services, \
-    get_bom_with_component_setuptools_complete, get_bom_with_external_references
+    MOCK_UUID_1, get_bom_just_complete_metadata, MOCK_UUID_2, MOCK_UUID_3, TEST_UUIDS, get_bom_with_services_complex, \
+    get_bom_with_nested_services, get_bom_with_component_setuptools_complete, get_bom_with_external_references
 from tests.base import BaseJsonTestCase
 
 
@@ -178,7 +177,7 @@ def test_bom_v1_3_component_with_vulnerability(self) -> None:
             fixture='bom_setuptools.json'
         )
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_1)
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value=MOCK_UUID_1)
     def test_bom_v1_4_with_metadata_component(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_just_complete_metadata(), schema_version=SchemaVersion.V1_4,
@@ -186,7 +185,7 @@ def test_bom_v1_4_with_metadata_component(self, mock_uuid: Mock) -> None:
         )
         mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_2)
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value=MOCK_UUID_2)
     def test_bom_v1_3_with_metadata_component(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_just_complete_metadata(), schema_version=SchemaVersion.V1_3,
@@ -194,7 +193,7 @@ def test_bom_v1_3_with_metadata_component(self, mock_uuid: Mock) -> None:
         )
         mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_3)
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value=MOCK_UUID_3)
     def test_bom_v1_2_with_metadata_component(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_just_complete_metadata(), schema_version=SchemaVersion.V1_2,
@@ -202,95 +201,77 @@ def test_bom_v1_2_with_metadata_component(self, mock_uuid: Mock) -> None:
         )
         mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_1)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_3)
-    def test_bom_v1_4_services_simple(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_4_services_simple(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_services_simple(), schema_version=SchemaVersion.V1_4,
             fixture='bom_services_simple.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_2)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_4)
-    def test_bom_v1_3_services_simple(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_3_services_simple(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_services_simple(), schema_version=SchemaVersion.V1_3,
             fixture='bom_services_simple.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_4)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_5)
-    def test_bom_v1_2_services_simple(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_2_services_simple(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_services_simple(), schema_version=SchemaVersion.V1_2,
             fixture='bom_services_simple.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_6)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_4)
-    def test_bom_v1_4_services_complex(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_4_services_complex(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_services_complex(), schema_version=SchemaVersion.V1_4,
             fixture='bom_services_complex.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_5)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_3)
-    def test_bom_v1_3_services_complex(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_3_services_complex(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_services_complex(), schema_version=SchemaVersion.V1_3,
             fixture='bom_services_complex.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_4)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_2)
-    def test_bom_v1_2_services_complex(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_2_services_complex(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_services_complex(), schema_version=SchemaVersion.V1_2,
             fixture='bom_services_complex.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_1)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_2)
-    def test_bom_v1_4_services_nested(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_4_services_nested(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_nested_services(), schema_version=SchemaVersion.V1_4,
             fixture='bom_services_nested.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_3)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_4)
-    def test_bom_v1_3_services_nested(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_3_services_nested(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_nested_services(), schema_version=SchemaVersion.V1_3,
             fixture='bom_services_nested.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_5)
-    @patch('cyclonedx.model.service.uuid4', return_value=MOCK_UUID_6)
-    def test_bom_v1_2_services_nested(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_2_services_nested(self, mock_uuid: Mock) -> None:
         self._validate_json_bom(
             bom=get_bom_with_nested_services(), schema_version=SchemaVersion.V1_2,
             fixture='bom_services_nested.json'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
     # Helper methods
     def _validate_json_bom(self, bom: Bom, schema_version: SchemaVersion, fixture: str) -> None:
diff --git a/tests/test_output_xml.py b/tests/test_output_xml.py
index 780e0de3..a2bed4bd 100644
--- a/tests/test_output_xml.py
+++ b/tests/test_output_xml.py
@@ -24,15 +24,11 @@
 from data import get_bom_with_component_setuptools_basic, get_bom_with_component_setuptools_with_cpe, \
     get_bom_with_component_toml_1, get_bom_with_component_setuptools_no_component_version, \
     get_bom_with_component_setuptools_with_release_notes, get_bom_with_component_setuptools_with_vulnerability, \
-    MOCK_UUID_1, MOCK_UUID_2, MOCK_UUID_3, MOCK_UUID_4, MOCK_UUID_5, MOCK_UUID_6, get_bom_just_complete_metadata, \
+    MOCK_UUID_1, MOCK_UUID_4, MOCK_UUID_5, MOCK_UUID_6, TEST_UUIDS, get_bom_just_complete_metadata, \
     get_bom_with_nested_services, get_bom_with_services_simple, get_bom_with_services_complex, \
     get_bom_with_component_setuptools_complete, get_bom_with_external_references
 from tests.base import BaseXmlTestCase
 
-TEST_UUIDS = [
-    MOCK_UUID_1, MOCK_UUID_2, MOCK_UUID_3, MOCK_UUID_4, MOCK_UUID_5, MOCK_UUID_6
-]
-
 
 class TestOutputXml(BaseXmlTestCase):
 
@@ -258,7 +254,7 @@ def test_bom_v1_0_component_with_vulnerability(self) -> None:
             fixture='bom_setuptools.xml'
         )
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_6)
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value=MOCK_UUID_6)
     def test_bom_v1_4_with_metadata_component(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_just_complete_metadata(), schema_version=SchemaVersion.V1_4,
@@ -266,7 +262,7 @@ def test_bom_v1_4_with_metadata_component(self, mock_uuid: Mock) -> None:
         )
         mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_5)
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value=MOCK_UUID_5)
     def test_bom_v1_3_with_metadata_component(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_just_complete_metadata(), schema_version=SchemaVersion.V1_3,
@@ -274,7 +270,7 @@ def test_bom_v1_3_with_metadata_component(self, mock_uuid: Mock) -> None:
         )
         mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_4)
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value=MOCK_UUID_4)
     def test_bom_v1_2_with_metadata_component(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_just_complete_metadata(), schema_version=SchemaVersion.V1_2,
@@ -282,7 +278,7 @@ def test_bom_v1_2_with_metadata_component(self, mock_uuid: Mock) -> None:
         )
         mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_1)
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value=MOCK_UUID_1)
     def test_bom_v1_1_with_metadata_component(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_just_complete_metadata(), schema_version=SchemaVersion.V1_1,
@@ -290,7 +286,7 @@ def test_bom_v1_1_with_metadata_component(self, mock_uuid: Mock) -> None:
         )
         mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_1)
+    @patch('cyclonedx.model.bom_ref.uuid4', return_value=MOCK_UUID_1)
     def test_bom_v1_0_with_metadata_component(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_just_complete_metadata(), schema_version=SchemaVersion.V1_0,
@@ -298,125 +294,101 @@ def test_bom_v1_0_with_metadata_component(self, mock_uuid: Mock) -> None:
         )
         mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_6)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_4_services_simple(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_4_services_simple(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_simple(), schema_version=SchemaVersion.V1_4,
             fixture='bom_services_simple.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_5)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_3_services_simple(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_3_services_simple(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_simple(), schema_version=SchemaVersion.V1_3,
             fixture='bom_services_simple.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_4)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_2_services_simple(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_2_services_simple(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_simple(), schema_version=SchemaVersion.V1_2,
             fixture='bom_services_simple.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_1)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_1_services_simple(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_1_services_simple(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_simple(), schema_version=SchemaVersion.V1_1,
             fixture='bom_empty.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_1)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_0_services_simple(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_0_services_simple(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_simple(), schema_version=SchemaVersion.V1_0,
             fixture='bom_empty.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_6)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_4_services_complex(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_4_services_complex(self, mock_uuid4: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_complex(), schema_version=SchemaVersion.V1_4,
             fixture='bom_services_complex.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid4.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_5)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_3_services_complex(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_3_services_complex(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_complex(), schema_version=SchemaVersion.V1_3,
             fixture='bom_services_complex.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_4)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_2_services_complex(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_2_services_complex(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_complex(), schema_version=SchemaVersion.V1_2,
             fixture='bom_services_complex.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_3)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_1_services_complex(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_1_services_complex(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_services_complex(), schema_version=SchemaVersion.V1_1,
             fixture='bom_empty.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_6)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_4_services_nested(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_4_services_nested(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_nested_services(), schema_version=SchemaVersion.V1_4,
             fixture='bom_services_nested.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_5)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_3_services_nested(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_3_services_nested(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_nested_services(), schema_version=SchemaVersion.V1_3,
             fixture='bom_services_nested.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
-    @patch('cyclonedx.model.component.uuid4', return_value=MOCK_UUID_4)
-    @patch('cyclonedx.model.service.uuid4', side_effect=TEST_UUIDS)
-    def test_bom_v1_2_services_nested(self, mock_uuid_c: Mock, mock_uuid_s: Mock) -> None:
+    @patch('cyclonedx.model.bom_ref.uuid4', side_effect=TEST_UUIDS)
+    def test_bom_v1_2_services_nested(self, mock_uuid: Mock) -> None:
         self._validate_xml_bom(
             bom=get_bom_with_nested_services(), schema_version=SchemaVersion.V1_2,
             fixture='bom_services_nested.xml'
         )
-        mock_uuid_c.assert_called()
-        mock_uuid_s.assert_called()
+        mock_uuid.assert_called()
 
     # Helper methods
     def _validate_xml_bom(self, bom: Bom, schema_version: SchemaVersion, fixture: str) -> None: