Sequence Rule
This field applies to the Scheduler only.
During operation processing, if the Scheduler cannot allocate a required resource to a load, it places a request in the request queue of each member resource of the required resource group. Depending on how busy a resource is, its request queue may contain several requests at any given time. The Sequence Rule determines how the system sequences the requests for this resource in the queue.
The default Sequence Rule for a resource is Global Sequencing Rule, which specifies that the resource should use the Global Sequencing Rule, defined on the Scheduling Parameters form. The default Global Sequencing Rule is First In First Out; the requests are placed in the queue in the sequence in which they arrive (new requests are placed at the bottom of the queue).
In most situations, the default sequencing and selection rules are appropriate. When tailoring your production model further, consider keeping the configuration simple by using the default value for one rule and defining the other rule as needed. For example, use the default FIFO sequencing rule and define appropriate selection rules.
The following rules are available:
| When this Rule is Selected... | These Loads/Demands Appear First in the Queue |
|---|---|
| Global Sequencing Rule | (Default to the Global Sequencing Rule defined on the Scheduling Parameters form). |
| First In First Out | Loads that arrive first. |
| Last In First Out | Loads that arrive last. |
| High to Low Load Priority | Demands with the higher priority number. Priority is determined by the Priority field on the Job Orders form. |
| Low to High Load Priority | Demands with the lower priority number. |
| Earliest Job Due Date | Demands with the earliest due date. |
| Earliest Job Release Date | Demands with the earliest start date. |
| Shortest Time for Current Operation | Loads with the shortest time for the current operation. |
| Longest Time for Current Operation | Loads with the longest time for the current operation. |
| Longest Time for Any Subseq. Operation | Loads with the longest time for any subsequent operation. |
| Fewest Remaining Operations | Loads with the fewest remaining operations. |
| Least Est. Remaining Process Time | Loads with the least estimated remaining processing time. |
| Least Static Slack | Loads with the least static slack. Static slack is the remaining time to due date. |
| LASS/Remaining Operations (Least Average Static Slack Per Remaining Operations) | Loads with the least average time to due date per remaining operations (static slack divided by remaining number of operations). |
| LASS/Remaining Processing Time (Least Average Static Slack Per Remaining Processing Time) | Loads with the least average time to due date per remaining processing time (static slack divided by remaining process time). |
| Least Dynamic Slack | Loads with the least dynamic slack. Dynamic slack is the remaining time to due date minus the remaining processing time (static slack minus remaining processing time). |
| LADS/Remaining Operations (Least Average Dynamic Slack Per Remaining Operations) | Loads with the least average dynamic slack divided by number of remaining operations. |
| LADS/Remaining Processing Time (Least Average Dynamic Slack Per Remaining Processing Time) | Loads with the least average dynamic slack divided by remaining processing time. |
| Adjusted Dynamic Slack | Adjust dynamic slack to more heavily weight the loads in danger of becoming late (if dynamic slack >= 0, then divide by remaining processing time; otherwise multiply by remaining processing time). |
| Small Load | Loads with the smallest quantity. |
| Large Load | Loads with the largest quantity. |
| User Defined (24-39) | See Writing a Custom Scheduler Rule for more information about creating user-defined rules. |
See Using Scheduler Rules for more information about sequence rules.