Patent ID: 7603668

Claim:
A method of obtaining an applicability set of patches applicable to be installed on a given computer system having installed thereon one or more installed files or filesets, the patches residing in a patch database and organized into one or more patch trees each having a root patch, where the root patch is the newest patch in a given patch tree, each patch modifying one or more files or filesets, the method comprising: selecting a set of one or more patch trees each of which contains at least one patch that patches one or more of the given computer system's installed files or filesets; identifying, in the set of the patches that comprise each selected patch tree, one or more start patches, where a start patch is the oldest patch within a selected patch tree that patches one or more particular files or filesets installed on the given computer system; traversing the selected patch trees from each patch tree's start patches and progressing toward each patch tree's root patch, thereby traversing patches in the patch trees; adding the traversed patches to the applicability set; removing any start patch from a set of start patches where the start patch itself is installed on the given computer system and also where the start patch has one or more successor patches in the start patch's patch tree that are installed on the given computer system, a successor patch being an adjacent patch lying closer to the root patch end of a patch tree; and adding to the set of start patches an uninstalled immediate successor patch to such a removed start patch or to its installed successor patch closest to the root patch end of the start patch's patch tree.