Just found out for this one, solution is here: http://maven.apache.org/surefire/maven-failsafe-plugin/plugin-info.html
maven-failsafe-plugin, contrarely to maven-compiler-plugin for example, is NOT in the default maven build lifecycle.
Consequently, one must respect this tags hierarchy:
<project>
<build>
<pluginManagement>
<plugins>
<!-- For understanding only, below is the 'maven-compiler-plugin':
its path is 'project -> build -> pluginManagement -> plugins
-> plugin', because it's defaulty part of the maven build
lifecycle: we just 'manage' it -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
..
</plugin>
</plugins>
</pluginManagement>
<plugins>
<!-- HERE is the 'maven-failsafe-plugin':
its path is 'project -> build -> plugins ->
plugin', because it's NOT defaulty part of
the maven build lifecycle: we have to
'define' it, and not just manage it as
stated earlier -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
..
</plugin>
</plugins>
</build>
<project>
Quoting from the official documentation link: "To define the plugin version in your parent POM" and "To use the plugin goals in your POM or parent POM". One must pay attention to the difference.