diff --git a/servicenow_api/servicenow_models.py b/servicenow_api/servicenow_models.py
index 3762168..6c72f07 100644
--- a/servicenow_api/servicenow_models.py
+++ b/servicenow_api/servicenow_models.py
@@ -32,7 +32,7 @@ class ApplicationServiceModel(BaseModel):
     - ValueError: If 'application_id' is provided and not a string.
     """
 
-    application_id: str = None
+    application_id: Optional[str] = None
 
     @field_validator("application_id")
     def validate_string_parameters(cls, v):
@@ -67,7 +67,7 @@ class CMDBModel(BaseModel):
     - ValueError: If 'cmdb_id' is provided and not a string.
     """
 
-    cmdb_id: str = None
+    cmdb_id: Optional[str] = None
 
     @field_validator("cmdb_id")
     def validate_string_parameters(cls, v):
@@ -179,7 +179,7 @@ def validate_string_parameters(cls, v):
         return v
 
     @field_validator("sys_ids")
-    def validate_string_parameters(cls, v):
+    def validate_sys_ids_parameters(cls, v):
         """
         Validate specific string parameters to ensure they are a List
 
@@ -497,7 +497,7 @@ class ImportSetModel(BaseModel):
     - data (Dict): Dictionary containing additional data.
     """
 
-    table: str = None
+    table: Optional[str] = None
     import_set_sys_id: Optional[str] = None
     data: Optional[Dict] = None
 
@@ -644,7 +644,7 @@ class TableModel(BaseModel):
     The class includes field_validator functions for specific attribute validations.
     """
 
-    table: str = None
+    table: Optional[str] = None
     table_record_sys_id: Optional[str] = None
     name_value_pairs: Optional[Dict] = None
     sysparm_display_value: Optional[str] = None
diff --git a/test/test_servicenow_models.py b/test/test_servicenow_models.py
index d732aaa..4834eb6 100644
--- a/test/test_servicenow_models.py
+++ b/test/test_servicenow_models.py
@@ -25,7 +25,6 @@
 else:
     skip = False
 
-
 reason = "do not run on MacOS or windows OR dependency is not installed OR " + reason
 
 
@@ -33,12 +32,88 @@
     sys.platform in ["darwin"] or skip,
     reason=reason,
 )
-def test_servicenow_models():
-    # test Project model group_id
+def test_servicenow_article():
     article_sys_id = "asdofaisudfa098098as0df9a8s"
     article = KnowledgeManagementModel(article_sys_id=article_sys_id)
     assert article_sys_id == article.article_sys_id
 
 
+@pytest.mark.skipif(
+    sys.platform in ["darwin"] or skip,
+    reason=reason,
+)
+def test_servicenow_change():
+    change_request_sys_id = "asdofaisudfa098098as0df9a8s"
+    change = ChangeManagementModel(change_request_sys_id=change_request_sys_id)
+    assert change_request_sys_id == change.change_request_sys_id
+
+
+@pytest.mark.skipif(
+    sys.platform in ["darwin"] or skip,
+    reason=reason,
+)
+def test_servicenow_incident():
+    incident_id = "asdofaisudfa098098as0df9a8s"
+    incident = IncidentModel(incident_id=incident_id)
+    assert incident_id == incident.incident_id
+
+
+@pytest.mark.skipif(
+    sys.platform in ["darwin"] or skip,
+    reason=reason,
+)
+def test_servicenow_cicd():
+    result_id = "asdofaisudfa098098as0df9a8s"
+    cicd = CICDModel(result_id=result_id)
+    assert result_id == cicd.result_id
+
+
+@pytest.mark.skipif(
+    sys.platform in ["darwin"] or skip,
+    reason=reason,
+)
+def test_servicenow_application():
+    application_id = "asdofaisudfa098098as0df9a8s"
+    application = ApplicationServiceModel(application_id=application_id)
+    assert application_id == application.application_id
+
+
+@pytest.mark.skipif(
+    sys.platform in ["darwin"] or skip,
+    reason=reason,
+)
+def test_servicenow_table():
+    table_name = "users"
+    table = TableModel(table=table_name)
+    assert table_name == table.table
+
+
+@pytest.mark.skipif(
+    sys.platform in ["darwin"] or skip,
+    reason=reason,
+)
+def test_servicenow_import_set():
+    import_set_sys_id = "asdofaisudfa098098as0df9a8s"
+    import_set = ImportSetModel(import_set_sys_id=import_set_sys_id)
+    assert import_set_sys_id == import_set.import_set_sys_id
+
+
+@pytest.mark.skipif(
+    sys.platform in ["darwin"] or skip,
+    reason=reason,
+    )
+def test_servicenow_cmdb():
+    cmdb_id = "asdofaisudfa098098as0df9a8s"
+    cmdb = CMDBModel(cmdb_id=cmdb_id)
+    assert cmdb_id == cmdb.cmdb_id
+
+
 if __name__ == "__main__":
-    test_servicenow_models()
+    test_servicenow_article()
+    test_servicenow_change()
+    test_servicenow_incident()
+    test_servicenow_cicd()
+    test_servicenow_application()
+    test_servicenow_table()
+    test_servicenow_import_set()
+    test_servicenow_cmdb()