Reasons for creating user defined rules

The standard Scheduler is intended to support the logic required to model most manufacturing operations. However, some facilities have unique manufacturing processes. To handle these unique situations, you can customize the Scheduler in a variety of ways. You can:

• Create new rules for sequencing and selecting queued requests for a resource.
• Create rules for selecting a resource from a resource group.
• Create new logic for forming and separating batches.
• Create extended ways to interpret the setup and run times.
• Create rules for determining when a setup should occur.

An example of such a situation is a heat treating operation which must be followed by a second heating operation within a given length of time or the product may crack. This implies that, before the first heating operation starts, the Scheduler may have to look ahead to see if the second heating can be done within the time limit. It may also require selecting loads for the second operation based on the criticality with respect to the time between operations. To customize the Scheduler for this situation, you would create a rule that would not allocate the furnace for the first operation unless the furnace for the second operation would be available within the time limit. You would then create a resource selection rule for the second furnace to select the loads most critical with respect to the time limit.

Another example of special logic can be found in the processing of food and other agricultural products where availability of storage for intermediate products is a serious constraint. Before a product can begin processing, it may be necessary to determine if a downstream storage bin is available for the product. If a bin is available, it may be necessary to reserve that bin so competing groups of products cannot use it. In this case, you should customize a resource selection rule to perform this checking and reserving of storage.