diff --git a/playbooks/os-cinder-install.yml b/playbooks/os-cinder-install.yml
index 71e10c498f..c4798940a7 100644
--- a/playbooks/os-cinder-install.yml
+++ b/playbooks/os-cinder-install.yml
@@ -83,7 +83,7 @@
   include: common-playbooks/cinder.yml
   vars:
     cinder_hosts: "cinder_volume:!cinder_scheduler:!cinder_api"
-    cinder_serial: "{{ cinder_backend_serial | default('1') }}"
+    cinder_serial: "{{ cinder_backend_serial | default('1', '100%') }}"
 
 
 
@@ -91,7 +91,7 @@
   include: common-playbooks/cinder.yml
   vars:
     cinder_hosts: "cinder_backup:!cinder_volume:!cinder_scheduler:!cinder_api"
-    cinder_serial: "{{ cinder_backend_serial | default('1') }}"
+    cinder_serial: "{{ cinder_backend_serial | default(['1', '100%']) }}"
 
 
 
@@ -102,7 +102,6 @@
 - name: Refresh local facts after all software changes are made
   hosts: cinder_all
   gather_facts: no
-  max_fail_percentage: 20
   user: root
   environment: "{{ deployment_environment_variables | default({}) }}"
   tags:
@@ -145,7 +144,7 @@
 - name: Restart cinder agents to ensure new RPC object version is used
   hosts: cinder_backup,cinder_volume,cinder_scheduler
   gather_facts: no
-  serial: "{{ cinder_backend_serial | default('1') }}"
+  serial: "{{ cinder_backend_serial | default(['1', '100%']) }}"
   max_fail_percentage: 20
   user: root
   environment: "{{ deployment_environment_variables | default({}) }}"
diff --git a/playbooks/os-neutron-install.yml b/playbooks/os-neutron-install.yml
index 1152567d11..10849bf030 100644
--- a/playbooks/os-neutron-install.yml
+++ b/playbooks/os-neutron-install.yml
@@ -37,7 +37,6 @@
 - name: Prepare MQ/DB services
   hosts: neutron_all
   gather_facts: no
-  max_fail_percentage: 20
   user: root
   environment: "{{ deployment_environment_variables | default({}) }}"
   tags:
@@ -93,7 +92,7 @@
   include: common-playbooks/neutron.yml
   vars:
     neutron_hosts: "neutron_linuxbridge_agent:neutron_openvswitch_agent:!neutron_server"
-    neutron_serial: "{{ neutron_agent_serial | default('20%') }}"
+    neutron_serial: "{{ neutron_agent_serial | default('50%') }}"
 
 
 
@@ -101,4 +100,4 @@
   include: common-playbooks/neutron.yml
   vars:
     neutron_hosts: "neutron_all:!neutron_linuxbridge_agent:!neutron_openvswitch_agent:!neutron_server"
-    neutron_serial: "{{ neutron_other_serial | default('1') }}"
+    neutron_serial: "{{ neutron_other_serial | default('20%') }}"
diff --git a/playbooks/os-nova-install.yml b/playbooks/os-nova-install.yml
index 0b848d236f..fcd16751fe 100644
--- a/playbooks/os-nova-install.yml
+++ b/playbooks/os-nova-install.yml
@@ -129,7 +129,7 @@
   include: common-playbooks/nova.yml
   vars:
     nova_hosts: "nova_compute:!nova_conductor:!nova_scheduler:!nova_consoleauth:!nova_api_os_compute:!nova_api_placement:!nova_api_metadata:!nova_console"
-    nova_serial: "{{ nova_compute_serial | default('20%') }}"
+    nova_serial: "{{ nova_compute_serial | default('50%') }}"
 
 
 
diff --git a/playbooks/rabbitmq-install.yml b/playbooks/rabbitmq-install.yml
index e88fcc89c8..bc99cbdc51 100644
--- a/playbooks/rabbitmq-install.yml
+++ b/playbooks/rabbitmq-install.yml
@@ -44,7 +44,6 @@
 # http://www.rabbitmq.com/clustering.html#upgrading
 - name: Stop RabbitMQ nodes that are not the upgrader
   hosts: "{{ rabbitmq_host_group | default('rabbitmq_all') }}[1:]"
-  serial: 1
   max_fail_percentage: 0
   user: root
   tasks:
@@ -56,7 +55,7 @@
 
 - name: Install rabbitmq server
   hosts: "{{ rabbitmq_host_group | default('rabbitmq_all') }}"
-  serial: 1
+  serial: 20%
   max_fail_percentage: 20
   user: root
   roles: