Added maturity notes session again.

Issue-ID: INT-751

Change-Id: Id02724c63be6499f7b13ca8beedf116f2d9beb9b
Signed-off-by: helenc878 <helen.chen@huawei.com>
diff --git a/docs/release/index.rst b/docs/release/index.rst
index 81610e5..c438dcb 100644
--- a/docs/release/index.rst
+++ b/docs/release/index.rst
@@ -151,6 +151,16 @@
 Project specific details are in the :ref:`release notes<doc-releaserepos>`
 for each project.
 
+.. index:: maturity

+ONAP Maturity Testing Notes
+===========================
+For the Casablanca release, ONAP continues to improve in multiple areas of 
+Scalability, Security, Stability and Performance (S3P) metrics.

+The Integration team ran the 72 hours stability testing (100% passing rate) 
+and full resilience testing (96.9% passing rate) at ONAP OpenLabs. More details in :ref:`ONAP Maturity Testing Notes <integration-s3p>` 
+
 Licenses
 ========
 ONAP Source Code is licensed under the `Apache Version 2 License