def compare_versions(old_version, new_version):
    """ 
    Compare specified version and return True if new version is strictly greater than old one

    Args:
        old_version (string): old version
        new_version (string): new version

    Returns:
        bool: True if new version available
    """
    #check versions
    old_vers = tuple(map(int, (old_version.split(u'.'))))
    if len(old_vers)!=3:
        raise Exception('Invalid version "%s" format, only 3 digits format allowed' % old_version)

    new_vers = tuple(map(int, (new_version.split(u'.'))))
    if len(new_vers)!=3:
        raise Exception('Invalid version "%s" format, only 3 digits format allowed' % new_version)

    #compare version
    if old_vers<new_vers:
        return True

    return False