Allocation Rule

This field applies to the Scheduler only.

Select the rule the Scheduler will use to select a particular resource member from the resource group to allocate to a load being processed at an operation. All rules will select the required number of available resources.

When this Rule is Selected... This Resource Member is Selected
Cyclic Select the resources cyclically starting with the next resource listed after the previously selected one.
Least Mean Utilization The resource that has the least mean utilization. The calculation of utilization is based on the Summary Data field being selected on the resource record; if Summary Data is not selected on the resource or on the resource group, the Allocation Rule defaults to Select in Sequence (because the Scheduler did not collect utilization summaries and assumes utilization of 0 for all resources).
Longest Idle The resource that has had the longest continuous idle period prior to this request.
Minimum Setup Time The resource that has the minimum setup time for the first downstream operation.
Random Selection Randomly select the resource.
Reserved for Job The resource that is reserved for this job. If the required number is not available, available resources are chosen based on least current utilization.
Select in Sequence (Default Rule) The required number of resources, searching in the sequence in which the resource members are listed in the group definition.
8-39: User Defined See Writing a Custom Scheduler Rule for more information about creating user-defined rules.
Reserved for Job/Operation No Reallocation The resource that is reserved for this job, at this operation. When the resource group becomes unavailable, due to shift, the job being processed is not reallocated to another resource in the group. If the required number is not available, available resources are chosen based on the sequence (see the Select in Sequence rule).
Reserved for Job/Operation With Reallocation The resource that is reserved for this job, at this operation. When the resource group becomes unavailable, due to shift, the job being processed may be reallocated to another resource in the group. If the required number is not available, available resources are chosen based on the sequence (see the Select in Sequence rule).
Note:  Sometimes, an operation is partially complete when you start a Scheduler run (that is, the operation was not complete at the end of the last Scheduler run). When you start the Scheduler run, the system tries to allocate the same resource to the operation when the operation processing resumes. When you run the Scheduler, if a job was already started and operations are incomplete, the Scheduler starts processing that job before other jobs that haven't already started. Therefore, those loads compete for resources before the other non-started jobs.