Page 317 - ExtendSim User Guide
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Activity-Based Costing 291
How ExtendSim tracks costs
able cost rate comes from the Cost per time unit dialog item of the corresponding Resource Pool block.
When a resource is released by an Unbatch or Resource Pool Release block, the information stored in the cost array is updated to indicate that the resource is no longer combined with the cost accumulator.
Calculating costs
As previously mentioned, the Create block and activity, queue, and resource-type blocks are all capable of generating costs. As these blocks process cost accumulators, they will automatically calculate the cost and add it to the item’s _cost attribute. In addition, each cost-generating block will update its Total Cost information. This dialog item displays the total cost contrib- uted by that particular block only. The following sections briefly discuss how these calcula- tions are performed.
In the Create block
When a cost accumulator is generated, ExtendSim will add the fixed cost (Cost per use) of the Create block to the cost accumulator’s _cost attribute.
For each cost accumulator generated, ExtendSim also will add the fixed cost of the Create block to its Total cost dialog item.
In activity-type blocks
When a cost accumulator enters an activity-type block, ExtendSim will add the activity’s fixed cost (cost per item) to the cost accumulator’s _cost attribute. In addition, it will calculate the variable time-based cost (the processing or transportation cost of the activity and the wait- ing cost of any resources currently combined with the cost accumulator), and add it to the _cost attribute of the cost accumulator.
For each cost accumulator that passes through the block, ExtendSim also will add the fixed and variable cost contributed by that activity-type block (not including costs contributed by any resources combined with the cost accumulator) to that block’s Total cost dialog.
In queue-type blocks
Queue-type blocks have a checkbox labelled “Calculate waiting costs”. If that checkbox is selected when a cost accumulator enters a queue-type block, ExtendSim will calculate the time-based cost. This is composed of the waiting or storage cost of the cost accumulator as cal- culated from the cost accumulator’s _rate attribute and the variable cost of any resources cur- rently combined with cost accumulator. The time-based cost is added to the _cost attribute of the cost accumulator.
For each cost accumulator that passes through a queue-type block, ExtendSim also will add the waiting cost calculated from the cost accumulator’s _rate attribute (not including costs contrib- uted by any resources combined with the cost accumulator) to that block’s Total cost dialog item.
Discrete Event


































































































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