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226 Resources and Shifts
Modeling resources
Resources required from different pools
In the Multiple Pools example, there are three Resource Pool blocks, each with their own labor resource. Items require either Labor 1, Labor 2, or Labor 3.
Multiple Pools model: One laborer per piece required from any of the three pools
Because it will hold items that require resource pool units, the Queue’s type is set to resource pool queue. As shown in the Queue’s dialog, the three resource pools have been selected from popup menus in the table and the block is instructed to take the resource from any one of those pools. When an item enters the Queue, it will query each of the resource pools in the order that they are listed in the table (from top to bottom). In other words, if no resources are available in Pool 1, the Queue block will try Pool 2, and then Pool 3. If a resource is still not found, the material will be held in the Queue until the resource requirement is met by which- ever pool first has an available resource.
Queue block dialog
Note that the Queue block (Options tab) stores
the information about which pool the resource came from, and how many resources were used, in an attribute that attaches to the items processed. In this model, the information is stored in the attribute “Resource Name.” This attribute is used by the Resource Pool Release block to inform the appropriate pool when a resource is no longer in use.
The Multiple Pools model is similar to the Simple Resource Pool model in that each piece of material requires 1 laborer. However, in this model the laborer can come from one of three pools rather than from a pool of three laborers. As in the earlier example, modeling this process using the resource item/batching method would require complex logic to correctly route the resources.
Same resource used in multiple places
The Multiple Uses model has two parallel processes, each requiring laborers. Items waiting in both Queues (set to resource pool queue) require a labor resource from the same Resource Pool block, which has 3 laborers initially available. When an item enters one of the queues, a request is sent to the Resource Pool block for a labor resource. The requests are satisfied in the
Discrete Event

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