diff --git a/jobs/CHM_Run_Automation/config.xml b/jobs/CHM_Run_Automation/config.xml
index 0923b5cb5c9746c34debaf098c7516e13f5fb2d8..588ca2689d8d3a5f268547f14d3b316fb9f11a2b 100644
--- a/jobs/CHM_Run_Automation/config.xml
+++ b/jobs/CHM_Run_Automation/config.xml
@@ -4,14 +4,6 @@
   <description></description>
   <keepDependencies>false</keepDependencies>
   <properties>
-    <jenkins.model.BuildDiscarderProperty>
-      <strategy class="hudson.tasks.LogRotator">
-        <daysToKeep>1</daysToKeep>
-        <numToKeep>3</numToKeep>
-        <artifactDaysToKeep>-1</artifactDaysToKeep>
-        <artifactNumToKeep>-1</artifactNumToKeep>
-      </strategy>
-    </jenkins.model.BuildDiscarderProperty>
     <com.dabsquared.gitlabjenkins.connection.GitLabConnectionProperty plugin="gitlab-plugin@1.5.12">
       <gitLabConnection>ylhealth</gitLabConnection>
     </com.dabsquared.gitlabjenkins.connection.GitLabConnectionProperty>
@@ -19,12 +11,22 @@
       <parameterDefinitions>
         <hudson.model.StringParameterDefinition>
           <name>Branch_Variable</name>
-          <description></description>
+          <description>There are two branches, descript as below
+1. master  
+2. develop</description>
           <defaultValue>master</defaultValue>
           <trim>false</trim>
         </hudson.model.StringParameterDefinition>
       </parameterDefinitions>
     </hudson.model.ParametersDefinitionProperty>
+    <jenkins.model.BuildDiscarderProperty>
+      <strategy class="hudson.tasks.LogRotator">
+        <daysToKeep>1</daysToKeep>
+        <numToKeep>3</numToKeep>
+        <artifactDaysToKeep>-1</artifactDaysToKeep>
+        <artifactNumToKeep>-1</artifactNumToKeep>
+      </strategy>
+    </jenkins.model.BuildDiscarderProperty>
   </properties>
   <scm class="hudson.plugins.git.GitSCM" plugin="git@3.11.0">
     <configVersion>2</configVersion>
@@ -70,7 +72,7 @@
       <enableCache>true</enableCache>
       <onlyCritical>true</onlyCritical>
     </hudson.plugins.robot.RobotPublisher>
-    <hudson.tasks.Mailer plugin="mailer@1.23">
+    <hudson.tasks.Mailer plugin="mailer@1.24">
       <recipients>$SonarQube_Administrator</recipients>
       <dontNotifyEveryUnstableBuild>false</dontNotifyEveryUnstableBuild>
       <sendToIndividuals>false</sendToIndividuals>