如何在MAVEN中保留更新的库？

On the development shop I work for, we have an internal MAVEN repository, to keep our libraries (proprietary & open-souce). A common problem that we face is that, sometimes, the open-source libraries in our local MAVEN repository gets obsolete. Is there an automatic way to keep all the open-source libraries I use in my MAVEN repository always updated? What do you suggest to resolve this issue?On the development shop I work for, we have an