Handling Resource Reallocation During Interruptions

When the Scheduler is processing a load of items on a job, it usually completes an operation and moves on to the next one in the routing, unless there is an interruption.

These situations can interrupt the load from being processed at an operation:

End of a shift
Start of a shift exception
Start of a holiday period

Three things happen when the load is interrupted:

Operation processing for the load stops.
The resources that have gone off-shift become unavailable.
All other resources allocated to the load remain allocated.

The system keeps track of each unavailable resource for the load. Once interrupted at an operation, a load must wait to resume operation processing until the system can again allocate all of the load's needed resources.

Setting Options to Handle Interruptions

You can set options to handle load interruptions as follows:

Process the load on a substitute resource.
Reserve the current resource (the one that is now off-shift).
Place the load back into the resource's request queue.

Use the Reallocate option on the Resource Group and the Allocation Type on the Resource to control interruptions. The diagram below illustrates the combinations of the two options:

Reallocate selected: The load frees the resource and tries to reallocate a resource from the same resource group. Any member of the resource group may serve as a substitute for the unavailable resource on this operation. The Scheduler does not consider the permanent/temporary state of the resource if Reallocate is selected on the resource group.
Reallocate not selected: The load can wait until that specific resource is available. The setting of the original resource's Allocation Type determines whether the load reserves that resource or must compete with other loads to reallocate it.
Allocation Type = Permanent: To resume processing at the operation, the interrupted load must regain the unavailable resource. It cannot allocate any other resource, and only this load can allocate the resource. Reallocation takes place when the resource becomes available, whether reallocation of any other needed resources succeeds or fails.
Allocation Type = Temporary: The interrupted load must regain the unavailable resource to resume operation processing. No other resource can substitute. The interrupted load must compete with other loads for the unavailable resource when it becomes available. The system places the load in the resource's request queue. Reallocation occurs only when the needed resource becomes available and when the interrupted load's request is selected.

Note: If one or more of the needed resources belongs to a resource group that has the Reallocate field cleared, reallocation is not possible until those resources become available again.

You will usually enable the Reallocate field for groups that contain labor resource types working on different shifts, but not for machine resource types.