java.lang.NoClassDefFoundError on a maven multi module project

I work on a maven multi module project. The modules are: the persistence module called entities packaged as jar, the services module called services packaged as jar and the web module called web packaged as war. The pom is the following:

<groupId>com.af</groupId>
<artifactId>eMuse</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>

<modules>
    <module>entities</module>
    <module>services</module>
    <module>web</module>
</modules>

Each module has his own application context file where I declare the beans.

entities-context.xml

<beans xmlns="http://ift.tt/GArMu6"
    xmlns:xsi="http://ift.tt/ra1lAU"
    xsi:schemaLocation="http://ift.tt/GArMu6 http://ift.tt/1jdM0fG">

    <bean id="actionDAO" class="com.af.dao.impl.ActionDAOImpl" />
    <bean id="milestoneDAO" class="com.af.dao.impl.MilestoneDAOImpl" />
    <bean id="milestoneMarksDAO" class="com.af.dao.impl.MilestoneMarksDAOImpl" />
    <bean id="milestoneTypeDAO" class="com.af.dao.impl.MilestoneTypeDAOImpl" />
    <bean id="studentDAO" class="com.af.dao.impl.StudentDAOImpl" />
    <bean id="studentsActionsDAO" class="com.af.dao.impl.StudentsActionsDAOImpl"></bean>
    <bean id="teamDAO" class="com.af.dao.impl.TeamDAOImpl" />
    <bean id="toolDAO" class="com.af.dao.impl.ToolDAOImpl" />
</beans>

services-context.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://ift.tt/GArMu6"
    xmlns:xsi="http://ift.tt/ra1lAU"
    xsi:schemaLocation="http://ift.tt/GArMu6 http://ift.tt/1jdM0fG">

    <bean id="studentService" class="com.af.service.impl.StudentServiceImpl"/>
</beans>

Also in the services pom.xml I added the dependency on the entities module.

<parent>
    <groupId>com.af</groupId>
    <artifactId>eMuse</artifactId>
    <version>1.0-SNAPSHOT</version>
</parent>
<artifactId>services</artifactId>

<dependency>
        <groupId>com.af</groupId>
        <artifactId>entities</artifactId>
        <version>1.0-SNAPSHOT</version>
</dependency>

And the web module configuration file

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://ift.tt/GArMu6"
    xmlns:xsi="http://ift.tt/ra1lAU" xmlns:context="http://ift.tt/GArMu7"
    xmlns:mvc="http://ift.tt/1bHqwjR" xmlns:p="http://ift.tt/1jdM0fE"
    xsi:schemaLocation="http://ift.tt/GArMu6 http://ift.tt/1CZCNBy
        http://ift.tt/GArMu7 http://ift.tt/1tY3uA9
        http://ift.tt/1bHqwjR http://ift.tt/YzZ6hD">


    <mvc:annotation-driven />

    <context:component-scan base-package="com.af" />
    <import resource="classpath*:entities-context.xml"/>
    <import resource="classpath*:services-context.xml"/>
    <!-- Tiles configuration -->

    <bean id="viewResolver"
        class="org.springframework.web.servlet.view.UrlBasedViewResolver">
        <property name="viewClass">
            <value>org.springframework.web.servlet.view.tiles2.TilesView</value>
        </property>
    </bean>
    <bean id="tilesConfigurer"
        class="org.springframework.web.servlet.view.tiles2.TilesConfigurer">
        <property name="definitions">
            <list>
                <value>/WEB-INF/tiles.xml</value>
            </list>
        </property>
    </bean>
    <mvc:default-servlet-handler />
</beans>

web/pom.xml

<parent>
    <groupId>com.af</groupId>
    <artifactId>eMuse</artifactId>
    <version>1.0-SNAPSHOT</version>
</parent>
<artifactId>web</artifactId>
<packaging>war</packaging>
<dependencies>
    <dependency>
        <groupId>com.af</groupId>
        <artifactId>services</artifactId>
        <version>1.0-SNAPSHOT</version>
        <exclusions>
            <exclusion>
                <groupId>com.af</groupId>
                <artifactId>entities</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
 <!-- other dependencies-->
 </dependencies>

And when i run:

 @Controller
 public class TestController {

    @Autowired
    private StudentService studentService;

    @RequestMapping(value="/index", method = RequestMethod.GET)
    public String test(Model model){

        StudentModel stud = StudentModelMapper.mapStudentDTO(studentService.getStudentById(1));
        model.addAttribute("name", stud.getFirstName());
        return "index";
    }


 }

I get the exception:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'testController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.af.service.StudentService com.af.controller.TestController.studentService; nested exception is java.lang.NoClassDefFoundError: Lcom/af/dao/StudentDAO;

Can anyone tell me what i am doing wrong?