Changes have done as per review comments.

Change1:Reframed the Error Message.
Change2:Renamed the test methods.
Change3:Added the TODO comments for future references.

osc-server/src/main/java/org/osc/core/broker/service/validator/DeleteDistributedApplianceRequestValidator.java

@@ -75,7 +75,7 @@ private void validateDAReferenceToSfcAndSecurityGroup(EntityManager em, Distribu
             try {
                 validateVSReferenceToSfcAndSecurityGroup(em, vs);
             } catch (VmidcBrokerValidationException ex) {
-                throw new VmidcBrokerValidationException(da.getName() + " " + ex.getMessage());
+                throw new VmidcBrokerValidationException(String.format("Cannot delete the distributed appliance '%s' reason:",da.getName())+" "+ex.getMessage());
             }
         }
     }
@@ -94,12 +94,10 @@ private void validateSfcReferenceToSecurityGroup(EntityManager em, ServiceFuncti
         String sgNames = sgList.stream().filter(sg -> !sg.getMarkedForDeletion()).map(sg -> sg.getName())
                 .collect(Collectors.joining(", "));
         if (!sgNames.isEmpty()) {
-            throw new VmidcBrokerValidationException(String.format(
-                    "distributed appliance cannot be deleted which is currently referencing Service Function Chain '%s' and binded to a SecurityGroup(s) '%s'",
+            throw new VmidcBrokerValidationException(String.format("Service Function Chain '%s' and binded to a Security Group(s) '%s'",
                     sfc.getName(), sgNames));
         } else if (!sfc.getMarkedForDeletion() && sfc != null) {
-            throw new VmidcBrokerValidationException(String.format(
-                    "distributed appliance cannot be deleted which is currently referencing Service Function Chain '%s'",
+            throw new VmidcBrokerValidationException(String.format("Service Function Chain '%s'",
                     sfc.getName()));
         }
     }

osc-server/src/test/java/org/osc/core/broker/service/request/DeleteDistributedApplianceRequestValidatorTest.java

@@ -43,7 +43,8 @@
 import org.powermock.api.mockito.PowerMockito;
 import org.powermock.core.classloader.annotations.PrepareForTest;
 import org.powermock.modules.junit4.PowerMockRunner;
-
+//TODO balmukund: Because the class under test now has a dependency on a complex DB query listReferencedVSBySecurityGroup it must be refactored to use an in mem db.
+// Until then powermock is being used to mock static dependencies. This should be removed when this refactoring happens.
 @RunWith(PowerMockRunner.class)
 @PrepareForTest({SecurityGroupEntityMgr.class,DistributedApplianceEntityMgr.class})
 public class DeleteDistributedApplianceRequestValidatorTest {
@@ -137,8 +138,10 @@ public void testValidateAndLoad_WithNonForceDeleteRequestAndMarkedForDeletionDA_
         Assert.assertEquals("The received ID in non force delete case  is different than expected VALID_ID_FOR_DELETION.", VALID_ID_FOR_DELETION, da.getId());
     }
 
+    //TODO balmukund: Because the class under test now has a dependency on a complex DB query listReferencedVSBySecurityGroup it must be refactored to use an in mem db.
+    // until then Powermock is being used to mock static dependencies. This should be removed when this refactoring happens.
     @Test
-    public void testValidateAndLoad_WhenChainedToSfcDeleteRequest_ThrowsValidationException() throws Exception {
+    public void testValidateAndLoad_WhenChainedToSfc_ThrowsValidationException() throws Exception {
         // Arrange
         final Long VALID_ID_WITH_SFC = 4l;
         DistributedAppliance da = createDA(VALID_ID_WITH_SFC, false);
@@ -163,7 +166,7 @@ public void testValidateAndLoad_WhenChainedToSfcDeleteRequest_ThrowsValidationEx
     }
 
     @Test
-    public void testValidateDAReferenceToSfcAndSecurityGroup_WhenChainedToSfcAndSgDeleteRequest_ThrowsValidationException()
+    public void testValidateAndLoad_WhenChainedToSfcAndSg_WhenSfcMode_ThrowsValidationException()
             throws Exception {
         // Arrange
         final Long VALID_ID_WITH_SFC = 4l;
@@ -185,17 +188,15 @@ public void testValidateDAReferenceToSfcAndSecurityGroup_WhenChainedToSfcAndSgDe
         Mockito.when(this.em.find(Mockito.eq(DistributedAppliance.class), Mockito.eq(VALID_ID_WITH_SFC)))
                 .thenReturn(da);
         this.exception.expect(VmidcBrokerValidationException.class);
-        this.exception.expectMessage(
-                String.format(
-                        "distributed appliance cannot be deleted which is currently referencing Service Function Chain '%s' and binded to a SecurityGroup(s) '%s'",
-                        sfc.getName(), sg.getName()));
+        this.exception.expectMessage(String.format("Service Function Chain '%s' and binded to a Security Group(s) '%s'",
+                sfc.getName(), sg.getName()));
 
         // Act
         this.validator.validateAndLoad(createRequest(VALID_ID_WITH_SFC, false));
     }
 
     @Test
-    public void testValidateDAReferenceToSfcAndSecurityGroup_WhenChainedToSfcDeleteRequest_ThrowsValidationException()
+    public void testValidateAndLoad_WhenChainedToSfc_WhenSfcMode_ThrowsValidationException()
             throws Exception {
         // Arrange
         final Long VALID_ID_WITH_SFC = 4l;
@@ -212,10 +213,7 @@ public void testValidateDAReferenceToSfcAndSecurityGroup_WhenChainedToSfcDeleteR
         Mockito.when(em.find(Mockito.eq(DistributedAppliance.class), Mockito.eq(VALID_ID_WITH_SFC)))
                 .thenReturn(da);
         this.exception.expect(VmidcBrokerValidationException.class);
-        this.exception.expectMessage(
-                String.format(
-                        "distributed appliance cannot be deleted which is currently referencing Service Function Chain '%s'",
-                        sfc.getName()));
+        this.exception.expectMessage(String.format("Service Function Chain '%s'",sfc.getName()));
 
         // Act
         this.validator.validateAndLoad(createRequest(VALID_ID_WITH_SFC, false));