Ready processing and candidates
A change package can refer to resource definitions from many CICS® configurations. When you mark a change package as "ready", you select a migration scheme that identifies a set of source and target CICS configurations. Only the resource definitions from the source CICS configurations are candidates for migration. If a change package does not refer to any resource definitions from the source CICS configurations, then there are no candidates; there is nothing to migrate, and you cannot mark the change package as ready.

When you mark a change package as ready, CICS Configuration Manager calculates and stores checksums of the candidates. Later, when you migrate the change package, CICS Configuration Manager calculates new checksums and compares them with the stored values. If any of the checksums is different, it means that the candidates have been edited, and CICS Configuration Manager does not allow the migration. This protects you from migrating unexpected changes.
Specifically, if any of the following items has changed, then CICS Configuration Manager does not allow the migration:
- List of candidates
- Attribute values of the candidates
- Names of source and target CICS configurations used by the migration scheme
Names of transformation rule sets or transformation groups used by the migration scheme
Updates to the following items do not affect change package readiness:
- The data set name of a CSD file or the name of a CICSPlex® SM context that is associated with a CICS configuration
- Resource definitions in the change package that are not candidates for the selected migration scheme
- Transformation rules
- Transformation variables and their values
CICS Configuration Manager calculates candidate checksums from a normalized resource definition record format, not the record format stored in the CSD file or the CICSPlex SM data repository. This normalized format is independent of:
- Whether the resource definition is stored in a CSD file or a CICSPlex SM data repository.
- The CICS release.
- Whether attribute values have been left blank, or explicitly specified as their default values.
- Whether attributes values have been specified that are literally different but effectively identical. For example, the values Y and YES are literally different but for some attributes are effectively identical.
- The time stamp of the resource definition.
By comparing resource definitions in a normalized format, and referring to CICS configuration names rather than the underlying CSD file or context, CICS Configuration Manager allows you to upgrade to a new CICS release, change the names of CSD files and contexts, or even move resource definitions between CSD files and CICSPlex SM data repositories, all without affecting change package readiness.