AGENDA Conveyors Arrivals element Schedules element Verification TYPES OF CONVEYORS Non-Accumulating Accumulating CONVEYOR RELATED STRUCTURES Blocks Access Convey Exit Elements Conveyors Segments Animation ACCESS BLOCK Holds the entity in a queue until sufficient space is available on the conveyor for the entity Entities may access more than one conveyor unit CONVEY BLOCK Transfers the entity to another point on the conveyor EXIT BLOCK Releases conveyor cells accessed by the entity CONVEYORS ELEMENT Defines characteristics of the conveyors used in the model SEGMENTS ELEMENT Defines the conveyor's actual path in terms of a series of connecting segments between stations that the conveyor serves. ANIMATION Stations Entities Pictures Segments Drawing tools ARRIVALS ELEMENT Force entities to appear Modeling customers waiting before opening time Make entities appear for demonstration purposes ... ARRIVALS ELEMENT Generates entities from within the experiment Types operand... Time operand... Batch size Assignments Needs to have an identifier number ARRIVALS TYPE OPERAND ARRIVALS TIME OPERAND Time First Start of replication Last End of replication Warmup End of warmup period from replicate element Every Act like a create block Keyhit Whenever the specified key is pressed SCHEDULES Allows capacity of resources to change over time Specified by pairs of resource capacity and capacity duration Schedule must be identified by name not a number Must be referenced in resource element Capacity entity rule from resources element Ignore – Waits until any service is over then goes on the remaining break Preempt – Immediately goes on a break Wait – Waits until any service is over then goes on a full break VERIFICATION The process of insuring that the model operates as intended Include all of the components specified under the system definition phase…. Actually able to run without any errors or warnings… INCLUDE ALL OF THE COMPONENTS A divide and conquer approach… Subroutine view approach A DIVIDE AND CONQUER APPROACH Break the larger more detailed model into a smaller simpler higher level model Make a series of enhancements to the simple model Enhancements to the detail of the existing components Expand the mode to include other components GETTING TO RUN WITHOUT ERRORS Use animation for verification… Manually advance the simulation clock… Write to an output file… USE ANIMATION FOR VERIFICATION Use different entity pictures for different types of entities Follow the entities through the system Change the entity pictures Displays Digital Displays of variables or entity values Plots of variables or entity values Levels of system statistics MANUALLY ADVANCE THE SIMULATION CLOCK Simulation models run quickly in compressed time May be necessary to slow the model to observe problems Step through by individual events on the simulation clock VCR-like controls WRITE TO AN OUTPUT FILE Potentially useful, but difficult to use Provides a permanent record Event list Entity attributes Global variables ARENA VERIFICATION TOOLS Trace element Run controller Animation