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Resources and Shifts
Phase II: Organizing resources
Close the dialog Save and run
Save your model
Run the simulation and observe the results
☞ For extra assurance, compare your model to the “Final Car Wash RM2” model located at
Examples\Tutorials\Discrete Event\Advanced Resources.
Results
Go to the Results tab of the Resource Manager block
In the resource results frame, examine the results displayed in the table
Notice that Washer/Waxer_1 and Washer_1 are much more heavily utilized than Waxer_1. This is because:
• Waxer_1 can only wax cars and cars that need to be waxed represent only 25% of the cars coming into the car wash.
• Washer/Waxer_1 and Washer_1 can both be used when cars only need washing as well as when they need washing and waxing. Thus the remaining workload is distributed evenly between Washer/Waxer_1 and Washer_1.
• Howtheresourcerequirementexpressioniscomposedimpactswhichresourcesgetselected.
Since the ARM system attempts to satisfy resource requirement expressions in left to right order, and the model contains resource requirements that use OR logic, changing the way the statement for the requirements is written impacts the behavior of the system.
For example, there are three possible ways the Wash Requirement could have been written: 1) 1fromWasher/WaxerOR1fromWasher
2) 1fromWasherOR1fromWasher/Waxer
3) 1fromWasher
Likewise, there are two possible ways the Wash/Wax Requirement could have been written:
1) (1fromWasherAND1fromWaxer)OR1fromWasher/Waxer
2) 1fromWasher/WaxerOR(1fromWasherAND1fromWaxer)
Thus from a resource requirements perspective alone, there are six (3 x 2) different ways to configure this model.
Try experimenting with each configuration to determine which one produces the best system performance. (The Scenario Manager would be especially useful for doing that.) Use the Event Logging tab of the Resource Manager block to generate a resource transaction log in order to observe which resources are getting allocated to specific orders.
Gathering statistical information
The ARM system provides extensive data for analysis and there are a number of ways to observe and analyze results for this model:
• The Resource Manager’s Results tab contains individual and pool level statistics for advanced resources in the model. These statistics apply to the current simulation run and include utilization, the number of resource orders serviced, and so forth. The same informa-
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