Page 309 - ExtendSim User Guide
P. 309

Activity-Based Costing 283
Modeling with activity-based costing
• Adirectorfixedcost,whichisenteredastheCostperitemorCostperuseinblockdia- logs.
• The variable cost rate, entered in block dialogs as the waiting cost/time unit or processing cost/time unit.
You do not need to define all cost information in order to perform ABC. However, if even one cost field is defined as a positive, non-zero number, ExtendSim will automatically track costs when the simulation is run.
Cost accumulating items have their own fixed costs and variable cost rates. As they use resources, wait for processing, and are processed, they acquire additional costs from resources, queues, and activities.
The following information describes how and where to define costs.
Costs for cost accumulators
You specify costing information for a cost accumulator in the cost section or tab of the block that originates the item. Each cost accumulator can have a fixed cost per item, such as its direct materials cost, and a variable waiting or processing cost rate, which causes it to accumulate costs as it is stored or waits for processing.
Cost accumulators are usually generated by the Create block. They can also be provided by a Resource Item block, depending on a setting in its Cost tab.
Create block
Costing information is entered differently in the Create block depending on whether the block is set to Create items randomly or to Create items by schedule.
• IntheReceiveInventory model described on
page 282 the Create
block generates crates randomly. The Waiting cost/hour and the Cost
per item for each crate
are defined in the cost section of the block’s Options tab, as shown above.
• WhentheCreateblockgeneratesitemsbyschedule,youmustexplicitlyset_costand_rate system attributes (discussed in “Working with cost data” on page 287) for each cost accumu- lating item. The value of the _cost attribute should be set to the cost accumulator's fixed cost.
Cost section of Options tab; block set to “Create items randomly”
Discrete Event

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