A system and/or method determines applicability of patches for
installation on a computer system. The method includes determining
whether a set of patches is stored in memory of a computer system and, if
the set of patches is stored, returning the cached set of patches as an
applicability result; and, if the set of patches is not stored,
traversing patch chains to encounter patches in the patch chains.
Traversing the patch chains begins with start patches, and encountered
patches are added to the applicability result.