Page 264 - ExtendSim User Guide
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Resources and Shifts
Advanced Resource Management
Advanced Resource Management
In ExtendSim, Advanced Resource Management (ARM) is an integrated system for organizing resources, distinguishing between them, and allocating them throughout a model. ARM pro- vides a convenient and straightforward method for defining complex resource requirements for items as well as a flexible set of rules for how resources get allocated to them. And it provides automated methods for quickly changing resource information and generating statistical reports.
The ARM system is an advanced tool that is only available in the ExtendSim AT and Extend- Sim Suite packages.
The ExtendSim database feature provides the ARM system’s architectural framework. ARM uses an Advanced Resources database to represent, manage, and track the status and properties of resources, pools, and groups, as well as allocation and release rules. The database is auto- matically created when a Resource Manager block is added to a model.
☞ In the ARM system, resources are records that are stored in the Resources table of the Advanced Resources database.
In addition to the database, several blocks (listed on page 271) form integral parts of ARM. The Resource Manager is the central component of the system. It provides a dialog-based interface for creating and managing resources, requirements, policies, and release rules. Other blocks (Queue, Queue Equation, Resource Pool, Resource Pool Release, Shift, and Statistics) control or report various aspects of resources. Together with the ExtendSim database feature, these blocks comprise the ExtendSim Advanced Resource Management system.
☞ The ARM system can co-exist with the other resource modeling systems (items as resources and non-ARM resource pools). Thus models can use a mixture of resource modeling methods.
How Advanced Resource Management works
The basic mechanism for allocating and releasing resources using ARM is:
1) Themodelhasmultipletypesofresourceswithspecifiedproperties
2) Resourcerequirementsaredefined;eachresourcerequirementisaspecificationofhow many and what types of resources are needed
3) AQueueissettobeanadvancedresourcequeue
4) Dependingontheirneeds,itemsintheQueuerequestresources,thenwaituntiltheir resource requirements can be satisfied
5) Onceresourcesareallocatedtoitems,theitemsarereleasedfromtheQueue
6) ResourcesremainallocatedtoitemsuntiltheresourcesarereleasedbyResourcePool Release blocks
7) Shiftblockscanbeusedtobringadvancedresourcesonandoffschedule
8) Themanagementofresourcestatesandquantitiesandtheallocationandreleaseof resources is controlled by the Resource Manager
9) Asthemodelruns,discretetransactionsoccurbetweentheadvancedresourceblocksand an internal advanced resource database. These transactions are driven by item arrivals in the Queue and Resource Pool Release blocks, shift changes, and resource pool quantity changes.
Discrete Event

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