Suppose you have a large number of unit test cases and you don’t want them to be executed all at the same time during Maven build. You can simply achieve it via annotation @Category.
(1) Create empty class FastTests and SlowTests.
(2) In your test case class, categorize your test method using @Category annotation:

<profiles>
<profile>
<id>SlowTests</id>
<properties>
<testcase.groups>com.sap.SlowTests</testcase.groups>
</properties>
</profile>
<profile>
<id>FastTests</id>
<properties>
<testcase.groups>com.sap.FastTests</testcase.groups>
</properties>
</profile>
</profiles>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.13</version>
<dependencies>
<dependency>
<groupId>org.apache.maven.surefire</groupId>
<artifactId>surefire-junit47</artifactId>
<version>2.13</version>
</dependency>
</dependencies>
<configuration>
<groups>${testcase.groups}</groups>
</configuration>
</plugin>
</plugins>
</build>
(4)In my project, by default all 7 test methods will be executed during Maven build: