Multiple matching criteria for the resolution of dependencies

The execution of an operation or occurrence in the plan may be specified to depend on the completion of another operation or occurrence. The operation/occurrence that depends on another is termed successor. A successor depends on a predecessor. After a dependency is defined in the database, the process by which it is resolved in the plan can be defined as finding the best match between the operations or, if this is not possible, the occurrences that they are part of. The process takes as its primary basis the input arrival times of the successor and of the predecessor: starting from the input arrival time of the successor, the dependency is resolved when a predecessor with the input arrival time that best matches the selection criteria defined in the database is found.

As described in Specifying dependency resolution criteria, there are several options for defining in the Application Description how a dependency between predecessor and successor operations is resolved. The criterion chosen to pick a matching predecessor that best resolves the dependency can be that the matching predecessor is the one with:
  • The nearest preceding input arrival time.
  • The nearest input arrival time within the same day of the successor.
  • The closest input arrival time within a specified interval. The interval boundaries are calculated using an offset expressed in hours and minutes before or after the IA time of the successor. The interval can be timed entirely before, entirely after, or across the IA time of the successor.
  • The closest input arrival time within a specified interval. The interval boundaries are specified by a time and a number of days before or after the IA time of the successor. The interval can be timed entirely before, entirely after, or across the IA time of the successor.

In addition, the resolution of a normal dependency may be defined mandatory at plan level where, if the predecessor is not in the plan, the plan (LTP and DP) fails directly, or at control level where, if the predecessor is missing, a pending mandatory predecessor entry is added and the occurrence remains in waiting status. If no predecessor matches the specified criteria, the successor operation will not start until it is manually unblocked by the operator. The mandatory dependency resolution mechanism does not apply to conditional or cross dependencies.

Dependencies are defined in the database and resolved in the plans (long-term, current, and daily). In the long-term and daily plans, they are resolved when the batches run. In the current plan, they are resolved when occurrences are added dynamically through PIF, ETT, ISPF, or the Dynamic Workload Console. The next sections detail the mechanisms used for resolving dependencies at the different plan stages.