diff --git a/spec/models/service_template_transformation_plan_spec.rb b/spec/models/service_template_transformation_plan_spec.rb
index 2e275766332..7687863bc40 100644
--- a/spec/models/service_template_transformation_plan_spec.rb
+++ b/spec/models/service_template_transformation_plan_spec.rb
@@ -17,9 +17,11 @@
   end
 
   let(:transformation_mapping) { FactoryGirl.create(:transformation_mapping) }
+  let(:transformation_mapping2) { FactoryGirl.create(:transformation_mapping) }
   let(:apst) { FactoryGirl.create(:service_template_ansible_playbook) }
   let(:vm1) { FactoryGirl.create(:vm_or_template) }
   let(:vm2) { FactoryGirl.create(:vm_or_template) }
+  let(:vm3) { FactoryGirl.create(:vm_or_template) }
 
   let(:catalog_item_options) do
     {
@@ -37,6 +39,73 @@
     }
   end
 
+  let(:updated_catalog_item_options_with_vms_added) do
+    {
+      :name        => 'Transformation Plan Updated',
+      :description => 'an updated description',
+      :config_info => {
+        :transformation_mapping_id => transformation_mapping.id,
+        :pre_service_id            => apst.id,
+        :post_service_id           => apst.id,
+        :actions                   => [
+          {:vm_id => vm1.id.to_s, :pre_service => true, :post_service => false},
+          {:vm_id => vm2.id.to_s, :pre_service => true, :post_service => true},
+          {:vm_id => vm3.id.to_s, :pre_service => true, :post_service => true}
+        ],
+      }
+    }
+  end
+
+  let(:updated_catalog_item_options_with_vms_removed) do
+    {
+      :name        => 'Transformation Plan Updated',
+      :description => 'an updated description',
+      :config_info => {
+        :transformation_mapping_id => transformation_mapping.id,
+        :pre_service_id            => apst.id,
+        :post_service_id           => apst.id,
+        :actions                   => [
+          {:vm_id => vm1.id.to_s, :pre_service => true, :post_service => false}
+        ],
+      }
+    }
+  end
+
+  let(:updated_catalog_item_options_with_vms_added_and_removed) do
+    {
+      :name        => 'Transformation Plan Updated',
+      :description => 'an updated description',
+      :config_info => {
+        :transformation_mapping_id => transformation_mapping.id,
+        :pre_service_id            => apst.id,
+        :post_service_id           => apst.id,
+        :actions                   => [
+          {:vm_id => vm1.id.to_s, :pre_service => true, :post_service => false},
+          {:vm_id => vm3.id.to_s, :pre_service => true, :post_service => true}
+        ],
+      }
+    }
+  end
+
+  let(:updated_options_with_updated_transformation_mapping) do
+    {
+      :name        => 'Transformation Plan Updated',
+      :description => 'an updated description',
+      :config_info => {
+        :transformation_mapping_id => transformation_mapping2.id,
+        :pre_service_id            => apst.id,
+        :post_service_id           => apst.id,
+        :actions                   => [
+          {:vm_id => vm1.id.to_s, :pre_service => true, :post_service => false},
+          {:vm_id => vm2.id.to_s, :pre_service => true, :post_service => true}
+        ],
+      }
+    }
+  end
+
+  let(:miq_requests) { [FactoryGirl.create(:service_template_transformation_plan_request, :request_state => "finished")] }
+  let(:miq_requests_with_in_progress_request) { [FactoryGirl.create(:service_template_transformation_plan_request, :request_state => "active")] }
+
   describe '.public_service_templates' do
     it 'display public service templates' do
       st1 = FactoryGirl.create(:service_template_transformation_plan)
@@ -90,4 +159,143 @@
       )
     end
   end
+
+  describe '#update_catalog_item' do
+    it 'updates the associated transformation mapping' do
+      service_template = described_class.create_catalog_item(catalog_item_options)
+      service_template.miq_requests = []
+      service_template.update_catalog_item(updated_options_with_updated_transformation_mapping)
+      expect(service_template.name).to eq('Transformation Plan Updated')
+      expect(service_template.transformation_mapping).to eq(transformation_mapping2)
+    end
+
+    it 'updates by adding new VMs to existing VMs and returns a transformation plan' do
+      service_template = described_class.create_catalog_item(catalog_item_options)
+      service_template.miq_requests = []
+      service_template.update_catalog_item(updated_catalog_item_options_with_vms_added)
+
+      expect(service_template.name).to eq('Transformation Plan Updated')
+      expect(service_template.transformation_mapping).to eq(transformation_mapping)
+      expect(service_template.vm_resources.collect(&:resource)).to match_array([vm1, vm2, vm3])
+      expect(service_template.vm_resources.collect(&:status)).to eq([ServiceResource::STATUS_QUEUED, ServiceResource::STATUS_QUEUED, ServiceResource::STATUS_QUEUED])
+      expect(service_template.vm_resources.find_by(:resource_id => vm1.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.vm_resources.find_by(:resource_id => vm2.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id, "post_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.vm_resources.find_by(:resource_id => vm3.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id, "post_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.config_info).to eq(updated_catalog_item_options_with_vms_added[:config_info])
+      expect(service_template.resource_actions.first).to have_attributes(
+        :action => 'Provision',
+        :fqname => described_class.default_provisioning_entry_point(nil)
+      )
+    end
+
+    it 'updates by removing some VMs from the existing VMs and returns a transformation plan' do
+      service_template = described_class.create_catalog_item(catalog_item_options)
+      service_template.miq_requests = []
+      service_template.update_catalog_item(updated_catalog_item_options_with_vms_removed)
+
+      expect(service_template.name).to eq('Transformation Plan Updated')
+      expect(service_template.transformation_mapping).to eq(transformation_mapping)
+      expect(service_template.vm_resources.collect(&:resource)).to match_array([vm1])
+      expect(service_template.vm_resources.collect(&:status)).to eq([ServiceResource::STATUS_QUEUED])
+      expect(service_template.vm_resources.find_by(:resource_id => vm1.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.config_info).to eq(updated_catalog_item_options_with_vms_removed[:config_info])
+      expect(service_template.resource_actions.first).to have_attributes(
+        :action => 'Provision',
+        :fqname => described_class.default_provisioning_entry_point(nil)
+      )
+    end
+
+    it 'updates by adding new VMs to the existing VMs and removing some VMs from the existing VMs and returns a transformation plan' do
+      service_template = described_class.create_catalog_item(catalog_item_options)
+      service_template.miq_requests = []
+      service_template.update_catalog_item(updated_catalog_item_options_with_vms_added_and_removed)
+
+      expect(service_template.name).to eq('Transformation Plan Updated')
+      expect(service_template.transformation_mapping).to eq(transformation_mapping)
+      expect(service_template.vm_resources.collect(&:resource)).to match_array([vm1, vm3])
+      expect(service_template.vm_resources.collect(&:status)).to eq([ServiceResource::STATUS_QUEUED, ServiceResource::STATUS_QUEUED])
+      expect(service_template.vm_resources.find_by(:resource_id => vm1.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.vm_resources.find_by(:resource_id => vm3.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id, "post_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.config_info).to eq(updated_catalog_item_options_with_vms_added_and_removed[:config_info])
+      expect(service_template.resource_actions.first).to have_attributes(
+        :action => 'Provision',
+        :fqname => described_class.default_provisioning_entry_point(nil)
+      )
+    end
+
+    it 'updates only the basic attributes' do
+      service_template = described_class.create_catalog_item(catalog_item_options)
+      service_template.miq_requests = []
+      service_template.update_catalog_item(:name => "Name updated", :description => "description updated")
+
+      expect(service_template.name).to eq('Name updated')
+      expect(service_template.description).to eq('description updated')
+      expect(service_template.transformation_mapping).to eq(transformation_mapping)
+      expect(service_template.vm_resources.collect(&:resource)).to match_array([vm1, vm2])
+      expect(service_template.vm_resources.collect(&:status)).to eq([ServiceResource::STATUS_QUEUED, ServiceResource::STATUS_QUEUED])
+      expect(service_template.vm_resources.find_by(:resource_id => vm1.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.vm_resources.find_by(:resource_id => vm2.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id, "post_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.config_info).to eq(catalog_item_options[:config_info])
+      expect(service_template.resource_actions.first).to have_attributes(
+        :action => 'Provision',
+        :fqname => described_class.default_provisioning_entry_point(nil)
+      )
+    end
+
+    it 'updates only the basic attributes when completed miq_requests are present' do
+      service_template = described_class.create_catalog_item(catalog_item_options)
+      service_template.miq_requests = miq_requests
+      service_template.update_catalog_item(updated_catalog_item_options_with_vms_added)
+
+      expect(service_template.name).to eq('Transformation Plan Updated')
+      expect(service_template.description).to eq('an updated description')
+      expect(service_template.transformation_mapping).to eq(transformation_mapping)
+      expect(service_template.vm_resources.collect(&:resource)).to match_array([vm1, vm2])
+      expect(service_template.vm_resources.find_by(:resource_id => vm1.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.vm_resources.find_by(:resource_id => vm2.id).options)
+        .to eq("pre_ansible_playbook_service_template_id" => apst.id, "post_ansible_playbook_service_template_id" => apst.id)
+      expect(service_template.config_info).to eq(catalog_item_options[:config_info])
+      expect(service_template.resource_actions.first).to have_attributes(
+        :action => 'Provision',
+        :fqname => described_class.default_provisioning_entry_point(nil)
+      )
+    end
+
+    it 'raises an exception when miq_request is in progress' do
+      service_template = described_class.create_catalog_item(catalog_item_options)
+      service_template.miq_requests = miq_requests_with_in_progress_request
+      expect do
+        service_template.update_catalog_item(updated_catalog_item_options_with_vms_added)
+      end.to raise_error(StandardError, 'Editing a plan in progress is prohibited')
+    end
+
+    it 'requires a transformation mapping' do
+      updated_catalog_item_options_with_vms_added[:config_info].delete(:transformation_mapping_id)
+
+      service_template = described_class.create_catalog_item(catalog_item_options)
+
+      expect do
+        service_template.update_catalog_item(updated_catalog_item_options_with_vms_added)
+      end.to raise_error(StandardError, 'Must provide an existing transformation mapping')
+    end
+
+    it 'requires selected vms' do
+      updated_catalog_item_options_with_vms_added[:config_info].delete(:actions)
+
+      service_template = described_class.create_catalog_item(catalog_item_options)
+
+      expect do
+        service_template.update_catalog_item(updated_catalog_item_options_with_vms_added)
+      end.to raise_error(StandardError, 'Must select a list of valid vms')
+    end
+  end
 end