diff --git a/spcs-three-tier/README.md b/spcs-three-tier/README.md
index 0bc00d2..7e5ea72 100644
--- a/spcs-three-tier/README.md
+++ b/spcs-three-tier/README.md
@@ -123,6 +123,24 @@ See the [documentation](https://other-docs.snowflake.com/en/native-apps/provider
 
 8. Click "Publish".
 
+
+#### Upgrade
+In the provider account
+
+alter application package spcs_app_pkg add version v1 using @spcs_app_pkg.napp.app_stage;
+alter application package spcs_app_pkg set default release directive version=v1 patch=0;
+
+add patch 
+alter application package spcs_app_pkg add patch for version v1 using @spcs_app_pkg.napp.app_stage;
+alter application package spcs_app_pkg set default release directive version=v1 patch=1; 
+
+add version v2
+alter application package spcs_app_pkg add version v2 using @spcs_app_pkg.napp.app_stage;
+alter application package spcs_app_pkg set default release directive version=v2 patch=1;
+
+Check the status:
+If you have multiple 
+
 ### Debugging
 There are some Stored Procedures to allow the Consumer to see the status
 and logs for the containers and services. These procedures are granted to the `app_admin`
diff --git a/spcs-three-tier/app/manifest.yml b/spcs-three-tier/app/manifest.yml
index 4f0f146..13b2be3 100644
--- a/spcs-three-tier/app/manifest.yml
+++ b/spcs-three-tier/app/manifest.yml
@@ -1,10 +1,10 @@
 manifest_version: 1
 version:
-  name: V1
+  name: versioned_schema
   label: "First Version"
 
 configuration:
-  grant_callback: v1.create_services
+  grant_callback: versioned_schema.create_services
 
 artifacts:
   setup_script: setup.sql
@@ -20,7 +20,7 @@ artifacts:
       - /spcs_app/napp/img_repo/eap_router
 
 lifecycle_callbacks:
-    version_initializer: v1.init
+    version_initializer: versioned_schema.init
 
 privileges:
   - BIND SERVICE ENDPOINT:
@@ -39,13 +39,13 @@ references:
         - SELECT
       object_type: VIEW
       multi_valued: false
-      register_callback: v1.register_single_callback
+      register_callback: versioned_schema.register_single_callback
   
   - WIKIPEDIA_EAI:
       label: "Wikipedia Access Integration"
       description: "EAI for Egress from NA+SPCS"
       privileges: [USAGE]
       object_type: EXTERNAL_ACCESS_INTEGRATION
-      register_callback: v1.register_single_callback
-      configuration_callback: v1.get_configuration
+      register_callback: versioned_schema.register_single_callback
+      configuration_callback: versioned_schema.get_configuration
       required_at_setup: true
\ No newline at end of file
diff --git a/spcs-three-tier/app/setup.sql b/spcs-three-tier/app/setup.sql
index 433b80e..9baf05b 100644
--- a/spcs-three-tier/app/setup.sql
+++ b/spcs-three-tier/app/setup.sql
@@ -3,11 +3,11 @@ CREATE APPLICATION ROLE IF NOT EXISTS app_user;
 CREATE SCHEMA IF NOT EXISTS app_public;
 GRANT USAGE ON SCHEMA app_public TO APPLICATION ROLE app_admin;
 GRANT USAGE ON SCHEMA app_public TO APPLICATION ROLE app_user;
-CREATE OR ALTER VERSIONED SCHEMA v1;
-GRANT USAGE ON SCHEMA v1 TO APPLICATION ROLE app_admin;
+CREATE OR ALTER VERSIONED SCHEMA versioned_schema;
+GRANT USAGE ON SCHEMA versioned_schema TO APPLICATION ROLE app_admin;
 
 
-CREATE OR REPLACE PROCEDURE v1.register_single_callback(ref_name STRING, operation STRING, ref_or_alias STRING)
+CREATE OR REPLACE PROCEDURE versioned_schema.register_single_callback(ref_name STRING, operation STRING, ref_or_alias STRING)
  RETURNS STRING
  LANGUAGE SQL
  AS $$
@@ -25,9 +25,9 @@ CREATE OR REPLACE PROCEDURE v1.register_single_callback(ref_name STRING, operati
       RETURN 'Operation ' || operation || ' succeeds.';
       END;
    $$;
-GRANT USAGE ON PROCEDURE v1.register_single_callback(STRING, STRING, STRING) TO APPLICATION ROLE app_admin;
+GRANT USAGE ON PROCEDURE versioned_schema.register_single_callback(STRING, STRING, STRING) TO APPLICATION ROLE app_admin;
 
-CREATE OR REPLACE PROCEDURE v1.get_configuration(ref_name STRING)
+CREATE OR REPLACE PROCEDURE versioned_schema.get_configuration(ref_name STRING)
 RETURNS STRING
 LANGUAGE SQL
 AS 
@@ -47,26 +47,33 @@ BEGIN
 END;	
 $$;
 
-GRANT USAGE ON PROCEDURE v1.get_configuration(STRING) TO APPLICATION ROLE app_admin;
+GRANT USAGE ON PROCEDURE versioned_schema.get_configuration(STRING) TO APPLICATION ROLE app_admin;
 
 -- The version initializer callback is executed after a successful installation, upgrade, or downgrade of an application object.
--- In case the application fails to upgrade, the version initializer of the previous (successful) version will be executed so you 
+-- In case the application fails to upgrade, the version initializer of the previous (successful) version will be executed so you
 -- can clean up application state that may have been modified during the failed upgrade.
-CREATE OR REPLACE PROCEDURE v1.init()
-RETURNS STRING 
+
+-- this is the first the version(version v1 patch 0) of the app package. We consider the case that when the
+-- app is upgraded to next version and try to alter the services and it fails. In that case
+-- it will fail back to version v1 patch 0 and call this procedure versioned_schema.init() to
+-- restore the services and app can fully function.
+CREATE OR REPLACE PROCEDURE versioned_schema.init()
+RETURNS STRING
 LANGUAGE SQL
-EXECUTE AS OWNER 
+EXECUTE AS OWNER
 AS
 $$
-BEGIN    
-    ALTER SERVICE IF EXISTS app_public.frontend FROM SPECIFICATION_FILE='frontend.yaml';
-    ALTER SERVICE IF EXISTS app_public.backend FROM SPECIFICATION_FILE='backend.yaml';
+BEGIN
+    --create services if not exist
+    call versioned_schema.create_services();
+    --wait for 300 seconds, but it will stop if two services have READY status,
+    -- or any of the services has the FAILED status.
+    select system$wait_for_services(300, 'app_public.backend', 'app_public.frontend');
+
     RETURN 'init complete';
 END $$;
 
-GRANT USAGE ON PROCEDURE v1.init() TO APPLICATION ROLE app_admin;
-
-CREATE OR REPLACE PROCEDURE v1.start_backend(pool_name VARCHAR)
+CREATE OR REPLACE PROCEDURE versioned_schema.start_backend(pool_name VARCHAR)
     RETURNS string
     LANGUAGE sql
     AS $$
@@ -78,9 +85,9 @@ BEGIN
     GRANT USAGE ON SERVICE app_public.backend TO APPLICATION ROLE app_user;
 END
 $$;
-GRANT USAGE ON PROCEDURE v1.start_backend(VARCHAR) TO APPLICATION ROLE app_admin;
+GRANT USAGE ON PROCEDURE versioned_schema.start_backend(VARCHAR) TO APPLICATION ROLE app_admin;
 
-CREATE OR REPLACE PROCEDURE v1.start_frontend(pool_name VARCHAR)
+CREATE OR REPLACE PROCEDURE versioned_schema.start_frontend(pool_name VARCHAR)
     RETURNS string
     LANGUAGE sql
     AS $$
@@ -95,10 +102,10 @@ BEGIN
     RETURN 'Service started. Check status, and when ready, get URL';
 END
 $$;
-GRANT USAGE ON PROCEDURE v1.start_frontend(VARCHAR) TO APPLICATION ROLE app_admin;
+GRANT USAGE ON PROCEDURE versioned_schema.start_frontend(VARCHAR) TO APPLICATION ROLE app_admin;
 
 
-CREATE OR REPLACE PROCEDURE v1.create_services(privileges array)
+CREATE OR REPLACE PROCEDURE versioned_schema.create_services()
  RETURNS STRING
  LANGUAGE SQL
  AS 
@@ -114,11 +121,15 @@ CREATE OR REPLACE PROCEDURE v1.create_services(privileges array)
         MAX_NODES = 1
         INSTANCE_FAMILY = CPU_X64_XS;
 
-        CALL v1.start_backend('backend_compute_pool');
-        CALL v1.start_frontend('frontend_compute_pool');
+        CALL versioned_schema.start_backend('backend_compute_pool');
+        CALL versioned_schema.start_frontend('frontend_compute_pool');
+
+        # needed for installation from listing/cross account
+        GRANT SERVICE ROLE app_public.frontend!ALL_ENDPOINTS_USAGE TO APPLICATION ROLE app_admin;
+
+       GRANT USAGE ON PROCEDURE versioned_schema.create_services( ) TO APPLICATION ROLE app_admin;
     END;
 $$;
-GRANT USAGE ON PROCEDURE v1.create_services(array) TO APPLICATION ROLE app_admin;
 
 
 CREATE OR REPLACE PROCEDURE app_public.stop_app()
@@ -133,7 +144,7 @@ END
 $$;
 GRANT USAGE ON PROCEDURE app_public.stop_app() TO APPLICATION ROLE app_admin;
 
-CREATE OR REPLACE PROCEDURE v1.app_url()
+CREATE OR REPLACE PROCEDURE versioned_schema.app_url()
     RETURNS string
     LANGUAGE sql
     AS
@@ -146,8 +157,8 @@ BEGIN
     RETURN ingress_url;
 END
 $$;
-GRANT USAGE ON PROCEDURE v1.app_url() TO APPLICATION ROLE app_admin;
-GRANT USAGE ON PROCEDURE v1.app_url() TO APPLICATION ROLE app_user;
+GRANT USAGE ON PROCEDURE versioned_schema.app_url() TO APPLICATION ROLE app_admin;
+GRANT USAGE ON PROCEDURE versioned_schema.app_url() TO APPLICATION ROLE app_user;
 
 -- Support functions
 EXECUTE IMMEDIATE FROM 'support.sql';
\ No newline at end of file
diff --git a/spcs-three-tier/app_for_upgrade/manifest.yml b/spcs-three-tier/app_for_upgrade/manifest.yml
new file mode 100644
index 0000000..7ef61b2
--- /dev/null
+++ b/spcs-three-tier/app_for_upgrade/manifest.yml
@@ -0,0 +1,48 @@
+manifest_version: 2
+version:
+  name: versioned_schema
+  label: "Second Version"
+
+artifacts:
+  setup_script: setup.sql
+
+  default_web_endpoint:
+    service: app_public.frontend
+    endpoint: app
+
+  container_services:
+    images:
+      - /spcs_app/napp/img_repo/eap_frontend
+      - /spcs_app/napp/img_repo/eap_backend
+      - /spcs_app/napp/img_repo/eap_router
+
+lifecycle_callbacks:
+    version_initializer: versioned_schema.init
+
+privileges:
+  - BIND SERVICE ENDPOINT:
+      description: "Ability to create ingress URLs."
+      required_at_setup: true
+  - CREATE COMPUTE POOL:
+      required_at_setup: true
+      description: "Enable appplication to create its own compute pool(s)"
+
+
+references:
+  - ORDERS_TABLE:
+      label: "Orders table"
+      description: "Orders table in TPC-H samples"
+      privileges:
+        - SELECT
+      object_type: VIEW
+      multi_valued: false
+      register_callback: versioned_schema.register_single_callback
+  
+  - WIKIPEDIA_EAI:
+      label: "Wikipedia Access Integration"
+      description: "EAI for Egress from NA+SPCS"
+      privileges: [USAGE]
+      object_type: EXTERNAL_ACCESS_INTEGRATION
+      register_callback: versioned_schema.register_single_callback
+      configuration_callback: versioned_schema.get_configuration
+      required_at_setup: true
\ No newline at end of file
diff --git a/spcs-three-tier/app_for_upgrade/setup.sql b/spcs-three-tier/app_for_upgrade/setup.sql
new file mode 100644
index 0000000..401ac76
--- /dev/null
+++ b/spcs-three-tier/app_for_upgrade/setup.sql
@@ -0,0 +1,151 @@
+CREATE APPLICATION ROLE IF NOT EXISTS app_admin;
+CREATE APPLICATION ROLE IF NOT EXISTS app_user;
+CREATE SCHEMA IF NOT EXISTS app_public;
+GRANT USAGE ON SCHEMA app_public TO APPLICATION ROLE app_admin;
+GRANT USAGE ON SCHEMA app_public TO APPLICATION ROLE app_user;
+CREATE OR ALTER VERSIONED SCHEMA versioned_schema;
+GRANT USAGE ON SCHEMA versioned_schema TO APPLICATION ROLE app_admin;
+
+
+CREATE OR REPLACE PROCEDURE versioned_schema.register_single_callback(ref_name STRING, operation STRING, ref_or_alias STRING)
+ RETURNS STRING
+ LANGUAGE SQL
+ AS $$
+      BEGIN
+      CASE (operation)
+         WHEN 'ADD' THEN
+            SELECT system$set_reference(:ref_name, :ref_or_alias);
+         WHEN 'REMOVE' THEN
+            SELECT system$remove_reference(:ref_name);
+         WHEN 'CLEAR' THEN
+            SELECT system$remove_reference(:ref_name);
+         ELSE
+            RETURN 'Unknown operation: ' || operation;
+      END CASE;
+      RETURN 'Operation ' || operation || ' succeeds.';
+      END;
+   $$;
+GRANT USAGE ON PROCEDURE versioned_schema.register_single_callback(STRING, STRING, STRING) TO APPLICATION ROLE app_admin;
+
+CREATE OR REPLACE PROCEDURE versioned_schema.get_configuration(ref_name STRING)
+RETURNS STRING
+LANGUAGE SQL
+AS 
+$$
+BEGIN
+  CASE (UPPER(ref_name))
+      WHEN 'WIKIPEDIA_EAI' THEN
+          RETURN OBJECT_CONSTRUCT(
+              'type', 'CONFIGURATION',
+              'payload', OBJECT_CONSTRUCT(
+                  'host_ports', ARRAY_CONSTRUCT('upload.wikimedia.org'),
+                  'allowed_secrets', 'NONE')
+          )::STRING;
+      ELSE
+          RETURN '';
+  END CASE;
+END;	
+$$;
+
+GRANT USAGE ON PROCEDURE versioned_schema.get_configuration(STRING) TO APPLICATION ROLE app_admin;
+
+-- The version initializer callback is executed after a successful run of the setup script.
+-- In case the versioned_schema.init() failed, the version initializer of the previous version will be executed
+CREATE OR REPLACE PROCEDURE versioned_schema.init()
+RETURNS STRING 
+LANGUAGE SQL
+EXECUTE AS OWNER 
+AS
+$$
+BEGIN    
+    ALTER SERVICE IF EXISTS app_public.frontend FROM SPECIFICATION_FILE='frontend.yaml';
+    ALTER SERVICE IF EXISTS app_public.backend FROM SPECIFICATION_FILE='backend.yaml';
+    select system$wait_for_services(300, 'app_public.backend', 'app_public.frontend');
+    RETURN 'init complete';
+END $$;
+
+CREATE OR REPLACE PROCEDURE versioned_schema.start_backend(pool_name VARCHAR)
+    RETURNS string
+    LANGUAGE sql
+    AS $$
+BEGIN
+    CREATE SERVICE IF NOT EXISTS app_public.backend
+        IN COMPUTE POOL Identifier(:pool_name)
+        FROM SPECIFICATION_FILE='backend.yaml'
+        QUERY_WAREHOUSE = 'WH_NAC';
+    GRANT USAGE ON SERVICE app_public.backend TO APPLICATION ROLE app_user;
+END
+$$;
+GRANT USAGE ON PROCEDURE versioned_schema.start_backend(VARCHAR) TO APPLICATION ROLE app_admin;
+
+CREATE OR REPLACE PROCEDURE versioned_schema.start_frontend(pool_name VARCHAR)
+    RETURNS string
+    LANGUAGE sql
+    AS $$
+BEGIN
+    CREATE SERVICE IF NOT EXISTS app_public.frontend
+        IN COMPUTE POOL Identifier(:pool_name)
+        FROM SPECIFICATION_FILE='frontend.yaml'
+        EXTERNAL_ACCESS_INTEGRATIONS=( reference('WIKIPEDIA_EAI') );
+    
+    GRANT USAGE ON SERVICE app_public.frontend TO APPLICATION ROLE app_user;
+
+    RETURN 'Service started. Check status, and when ready, get URL';
+END
+$$;
+GRANT USAGE ON PROCEDURE versioned_schema.start_frontend(VARCHAR) TO APPLICATION ROLE app_admin;
+
+
+CREATE OR REPLACE PROCEDURE versioned_schema.create_services(privileges array)
+ RETURNS STRING
+ LANGUAGE SQL
+ AS 
+ $$
+    BEGIN
+        CREATE COMPUTE POOL IF NOT EXISTS frontend_compute_pool
+        MIN_NODES = 1
+        MAX_NODES = 1
+        INSTANCE_FAMILY = CPU_X64_XS;
+
+        CREATE COMPUTE POOL IF NOT EXISTS backend_compute_pool
+        MIN_NODES = 1
+        MAX_NODES = 1
+        INSTANCE_FAMILY = CPU_X64_XS;
+
+        CALL versioned_schema.start_backend('backend_compute_pool');
+        CALL versioned_schema.start_frontend('frontend_compute_pool');
+    END;
+$$;
+GRANT USAGE ON PROCEDURE versioned_schema.create_services(array) TO APPLICATION ROLE app_admin;
+
+
+CREATE OR REPLACE PROCEDURE app_public.stop_app()
+    RETURNS string
+    LANGUAGE sql
+    AS
+$$
+BEGIN
+    DROP SERVICE IF EXISTS app_public.backend;
+    DROP SERVICE IF EXISTS app_public.frontend;
+END
+$$;
+GRANT USAGE ON PROCEDURE app_public.stop_app() TO APPLICATION ROLE app_admin;
+
+CREATE OR REPLACE PROCEDURE versioned_schema.app_url()
+    RETURNS string
+    LANGUAGE sql
+    AS
+$$
+DECLARE
+    ingress_url VARCHAR;
+BEGIN
+    SHOW ENDPOINTS IN SERVICE app_public.frontend;
+    SELECT "ingress_url" INTO :ingress_url FROM TABLE (RESULT_SCAN (LAST_QUERY_ID())) LIMIT 1;
+    RETURN ingress_url;
+END
+$$;
+GRANT USAGE ON PROCEDURE versioned_schema.app_url() TO APPLICATION ROLE app_admin;
+GRANT USAGE ON PROCEDURE versioned_schema.app_url() TO APPLICATION ROLE app_user;
+
+-- Support functions
+EXECUTE IMMEDIATE FROM 'support.sql';
\ No newline at end of file
diff --git a/spcs-three-tier/prepare/consumer_setup.sql b/spcs-three-tier/prepare/consumer_setup.sql
index 2acbe91..22573c1 100644
--- a/spcs-three-tier/prepare/consumer_setup.sql
+++ b/spcs-three-tier/prepare/consumer_setup.sql
@@ -1,4 +1,10 @@
 USE ROLE ACCOUNTADMIN;
+CREATE ROLE IF NOT EXISTS nac;
+GRANT CREATE APPLICATION ON ACCOUNT TO ROLE nac;
+GRANT CREATE INTEGRATION ON ACCOUNT TO ROLE nac;
+-- needed for app installation from a listing
+GRANT IMPORT SHARE ON ACCOUNT TO nac;
+
 -- (Mock) Consumer role
 GRANT ROLE nac TO ROLE ACCOUNTADMIN;
 CREATE WAREHOUSE IF NOT EXISTS wh_nac WITH WAREHOUSE_SIZE='XSMALL';
diff --git a/spcs-three-tier/prepare/provider_setup.sql b/spcs-three-tier/prepare/provider_setup.sql
index fec5a88..7fdb5ab 100644
--- a/spcs-three-tier/prepare/provider_setup.sql
+++ b/spcs-three-tier/prepare/provider_setup.sql
@@ -16,12 +16,6 @@ USE ROLE naspcs_role;
 CREATE DATABASE IF NOT EXISTS spcs_app;
 CREATE SCHEMA IF NOT EXISTS spcs_app.napp;
 
--- For Provider-side Testing
-USE ROLE ACCOUNTADMIN;
-CREATE ROLE IF NOT EXISTS nac;
-GRANT CREATE APPLICATION ON ACCOUNT TO ROLE nac;
-GRANT CREATE INTEGRATION ON ACCOUNT TO ROLE nac;
-
 -- Create the Image Repository
 USE ROLE naspcs_role;
 CREATE IMAGE REPOSITORY IF NOT EXISTS spcs_app.napp.img_repo;
diff --git a/spcs-three-tier/prepare/spcs_setup.sql b/spcs-three-tier/prepare/spcs_setup.sql
deleted file mode 100644
index cd712e7..0000000
--- a/spcs-three-tier/prepare/spcs_setup.sql
+++ /dev/null
@@ -1,5 +0,0 @@
-USE ROLE ACCOUNTADMIN;
-CREATE SECURITY INTEGRATION IF NOT EXISTS snowservices_ingress_oauth
-  TYPE=oauth
-  OAUTH_CLIENT=snowservices_ingress
-  ENABLED=true;
\ No newline at end of file
diff --git a/spcs-three-tier/register_callback.sql b/spcs-three-tier/register_callback.sql
index 09a94c2..dd180a5 100755
--- a/spcs-three-tier/register_callback.sql
+++ b/spcs-three-tier/register_callback.sql
@@ -1,4 +1,4 @@
 USE ROLE nac;
 USE WAREHOUSE wh_nac;
 GRANT USAGE ON WAREHOUSE wh_nac TO APPLICATION spcs_app_instance;
-CALL spcs_app_instance.v1.register_single_callback('ORDERS_TABLE' , 'ADD', SYSTEM$REFERENCE('VIEW', 'NAC_TEST.DATA.ORDERS', 'PERSISTENT', 'SELECT'));
+CALL spcs_app_instance.versioned_schema.register_single_callback('ORDERS_TABLE' , 'ADD', SYSTEM$REFERENCE('VIEW', 'NAC_TEST.DATA.ORDERS', 'PERSISTENT', 'SELECT'));
diff --git a/spcs-three-tier/setup.sh b/spcs-three-tier/setup.sh
index fb80d0a..3d6d84f 100755
--- a/spcs-three-tier/setup.sh
+++ b/spcs-three-tier/setup.sh
@@ -1,5 +1,4 @@
 set -e
-snow sql -f "prepare/spcs_setup.sql"
 snow sql -f "prepare/provider_setup.sql"
 snow sql -f "prepare/consumer_setup.sql"