Configure parallel execution of tests and classes in testng.xml

Got it now...

<suite name="Automation Suite" allow-return-values="true" verbose="1" parallel="tests" thread-count="2">    <test name="Login Test cases 01" parallel="classes" thread-count="2">        <parameter name="Operating_System" value="Windows 8"/>        <parameter name="Browser_Name" value="Internet Explorer"/>        <parameter name="Browser_Version" value="11"/>        <parameter name="Base_URL" value="https://www.google.com"/>        <classes>            <class name="com.automation.tool.Automation_01"/>            <class name="com.automation.tool.Automation_02"/>        </classes>    </test>    <test name="Login Test cases 02" parallel="classes" thread-count="2">        <parameter name="Operating_System" value="Windows XP"/>        <parameter name="Browser_Name" value="Mozilla Firefox"/>        <parameter name="Browser_Version" value="27"/>        <parameter name="Base_URL" value="https://www.google.com"/>        <classes>            <class name="com.automation.tool.Automation_01"/>            <class name="com.automation.tool.Automation_02"/>        </classes>    </test></suite>

In suite tag change the "parallel" attribute value from "tests" to "classes" for example:

If you wish to execute

1. tests in parallel then use = parallel="tests"
2. classes in parallel then use = parallel="classes"
3. Methods in parallel then use = parallel="methods"