Cumulative program temporary fix (PTF)
packages contain fixes for a given release of the i5/OS™ operating
system. The fixes contained in a cumulative PTF package are for the Licensed Internal Code and most licensed programs
that can be installed on that operating system release.
As the name implies, each package is cumulative; that is, it contains all of the fixes from the previous package plus additional fixes released since the previous package. Many, but not all, new fixes are included in cumulative packages. The fixes that are not included are typically applicable only to a specific user's situation or application. These fixes are not included for general availability to avoid introducing unwanted change and potential programming errors into a cumulative package where code quality has the highest priority. When you order the cumulative PTF package, you also receive the most recent database PTF group and the HIPER PTF group.
How often a cumulative package is available depends on the stage of the i5/OS release life cycle. During the first six months or so of general availability for a new release, a cumulative package can be available as often as every four to six weeks. After that time, cumulative packages are scheduled on a quarterly basis. After the i5/OS release has been available for a period of time, the frequency might decrease again. The frequency of availability depends on the number of new fixes to be added to the package.
You should install cumulative PTF packages quarterly in dynamic
environments and less frequently in stable ones. Also consider installing
cumulative fix packages before making major hardware or software changes to
your environment.