Arena modelingConceptual model can be converted into Arena model.

Arena model: connected building blocks.Building blocks must be parameterized.

Arena interface demo

Basic blocks

10

arriveA getonboardA

getoffboardA

getoffboardB leaveB

getonboardB arriveBleaveA

free place

wtA crAB atB

wtA atBcrBA

Create / Process / Disposebuilding blocks. Create Process Dispose

arriveA getonboardA getoffB leaveB

arriveB getonboardB getoffA leaveA

Adding resources

10

arriveA getonboardA

getoffboardA

getoffboardB leaveB

getonboardB arriveBleaveA

free place

wtA crAB atB

wtA atBcrBA

arriveA getonboardA getoffB leaveB

arriveB getonboardB getoffA leaveA

Splitting transitionsSeize two resources, release one when finished.

10

arriveA getonboardA

getoffboardA

getoffboardB leaveB

getonboardB arriveBleaveA

freeplace

atA atB

A2B

B2A

wtA crAB atB

wtA atBcrBA

Not directly possible in Arena:Seize Delay: seize and keep allSeize Delay Release: seize and return all.

Implementation: split!

Ferry implementation (ARENA)

10

arriveA getonboardA

getoffboardA

getoffboardB leaveB

getonboardB arriveBleaveA

freeplace

atA atB

A2B

B2A

wtA crAB atB

wtA atBcrBA

Split marked transitions.

Add "case" class for A2B and B2A.Create once, do not dispose.

Resources cannot be added.

ParameterizationArena building blocks are parameterized.Default parameters are set when installing blocks.Resource consumption/production parametersinferred from conceptual model.

Parameters to be added:- arrival distribution for create blocks (often negexp with a certain intensity),- duration for process blocks (sometimes 0 for blocks that result from splitting.

TestingAfter model construction, animated simulation is done.Press ► button and observe.Correct syntax errors.Unexpected results: adapt or explain.

If found correct, choose Run Setup,then Replication parameters tab.Select a moderate replication length andthen press ►►, wait until completionand examine the report.

Standard report: queue lengths for resources,processing times for entities.

Decide block

create

process

disposequeue ok?

decide_n

ok!decide_y

resource

Alternative paths:

Assign blockcreate disposex>=3

x=1

x+1

xx

x

xx

x<3

x x

Assignment:- attributes (per entity)- variables (global)"ordinary" programming

Other blocksIn some cases, the simulation should report on special data(e.g. expressions involving attributes and variables).This can be achieved by including the Report block.

Separate block is used for duplication of entities.Batch block is used for grouping entities.

For other Arena blocks, see the Arena bookW.D. Kelton, R.P. Sadowski, and D. Sturrock.Simulation with Arena, 3rd ed.McGraw-Hill, New York, 2004.

ClassworkA factory fabricates two types of products, X and Yand has (multiple) machines of types A,B and C respectively.Orders for product X have to pass through A and then C.Orders for Y have to pass through B and then C.The machine types A and B are different configurationsof the same machine. It is possible to reconfigure a machinefrom type A into type B and vice versa.If no cases are waiting for resource A and the queue lengthfor cases waiting for resource B exceeds N,a machine of type A is reconfigured to type B.If no cases are waiting for resource B and the queue lengthfor cases waiting for resource A exceeds M,a machine of type B is reconfigured to type A.Give conceptual model and Arena implementation.

Parameters

interarrival times X,Y : 1.0, resp. 0.85 minutes.machines A, B and C available: 2, 2, 4 (initially).Processing duration: 1.6 minutes per A/B stepand 1.8 minutes for any C step.Reconfiguration: 4 minutes (both A2B and B2A).Find most effective N, M .