A Bill of Materials - within Maven Context - is a way to list a set of libraries that are common to your project environment inside a pom file and set it as a parent for others. It is also possible to inherit a POM from another POM giving more control over the dependencies.
Just insert the parent tag below inside your pom file. The relativePath is not required but may be in handy if your project is using a pom that lies inside a closed eclipse project.
<parent>
<artifactId>parent-web-bom</artifactId>
<version>1.0</version>
<relativePath>../parent-web-bom</relativePath>
</parent>