Simulation Model Language, Lecture notes of Mathematical Modeling and Simulation

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Aslı Sencer Erdem Slide 1 Graduate Program in Business Information Systems BIS 517 Simulation with Arena Part 1

Behavior of Arena

• Arena is a true Windows application

 (^) Appearance, operation, functions, are standard  (^) Interoperability with other software (MS Office, CAD)  (^) Can interact, communicate with other software

• Assume you already know basics of Windows:

 (^) Disks, files, folders, paths  (^) Mousing, keyboarding  (^) Resizing, moving, maximizing, minimizing windows  (^) Menu operations  (^) Ctrl, Alt, Shift keys  (^) Cut, copy, paste  (^) Filling out dialog fields

Opening an Existing Model

• File/Open … or^ button

 (^) Navigate to desired disk/directory  (^) Click / Open or double-click Model 03-01.doe  (^) Book examples in … Rockwell Software\Arena\Arena Book  (^) Additional examples in … Rockwell Software\Arena
Examples

• Model window (usually on right side of Arena

window)  (^) Where model is built  (^) Resize, maximize, minimize, scroll/pan, zoom  (^) Can have multiple model windows open at once

• Cut, Copy, Paste within Arena, and between Arena

and other applications (when sensible) Why the .doe default extension to Arena model filenames?

Flowchart and Spreadsheet Views

• Model window split into two views

 (^) Flowchart view

• (^) Graphics
• (^) Process flowchart
• (^) Animation, drawing
• (^) Edit things by double-clicking on them, get into a dialog  (^) Spreadsheet view
• (^) Displays model data directly
• (^) Can edit, add, delete data in spreadsheet view
• (^) Displays all similar kinds of modeling elements at once  (^) Many model parameters can be edited in either view  (^) Horizontal splitter bar to apportion the two views  (^) View / Split Screen (or ) to see only the most recently selected view

Status Bar

• At very bottom of Arena window

• Displays various information sensitive to status

 Coordinates of cursor in “worldspace”  (^) Clock value, replication number when simulation is running

• Hide it by clearing (unchecking)^ View / Status Bar

Moving Around, Up, Down

in Flowchart View of Model Window

• Underlying^ world space^ for model

 (^) ( x , y ) coordinates in arbitrary units (> 32K in each direction)

• Pan^ with scroll bars, arrow keys

• Zoom^ in (down):^ or + key

• Zoom out (up):^ or^ –^ key

• See all at min altitude:^ or * key

• Named views

 (^) Save a pan/zoom view for different parts of model  (^) Assign a Hot key (case-sensitive)  (^) Access via View/Named Views … or? key

• Display^ grid^ (^ ),^ snap^ to grid (^ ) toggles

Flowchart Modules

• Describe dynamic processes

 (^) Nodes/places through which entities flow  (^) Typically connected to each other in some way

• Basic Process panel flowchart module types:

 (^) Create, Dispose, Process, Decide, Batch, Separate, Assign, Record

• Other panels – many other kinds

• Shape like flowcharting (also use colors for hints)

• Two ways to edit

 (^) Double-click to open up, then fill out dialogs  (^) Select (single-click) a module type in model or Project Bar, get all modules of that type in the spreadsheet view

Data Modules

• Set values, conditions, etc. for whole model

 No entity flow, no connections

• Basic Process panel data module types:

 Entity, Queue, Resource, Variable, Schedule, Set

• Other panels – many other kinds

• Icons in Project Bar look like little spreadsheets

• To use a data module, select it (single-click) in

the Project Bar, edit in spreadsheet view  Double-click where indicated to add new row  Right-click on row, column to do different things

• Only one instance of each kind of data module in

a model  (^) But each one can have many entries (rows)

Browsing Through Model 3-

• Open Model 03-01.mod (in Arena Book folder)

• Three flowchart modules (Create, Process,

Dispose)

• Entries in three data modules (Entity, Queue,

Resource)

• Animation objects

 Resource animation  Two plots  (^) Some (passive) labels, artwork

The Create Flowchart Module

• “Birth” node for entities

• Gave this instance of the Create-type module the

Name Part Arrives to System  (^) If we had other Create modules (we don’t) they’d all have different Names

• Double-click on module to open property dialog:

Editing Flowchart Modules in the

Spreadsheet View

• Alternative to dialog for each instance of a

module type

• See all instances of a module type at once

 (^) Convenient for seeing, editing lots of things at once

• Selecting a module in either flowchart or

spreadsheet view also selects it in the other view

• Click, double-click fields to view, edit

• Right-click to on left margin to delete a row (and

the associated module)

• Right-click in many fields to invoke Expression

Builder for help on constructing complex expressions with Arena variables (more later …)

The Entity Data Module

• A data module, so edit in spreadsheet view only

• View, edit aspects of different kinds of entities in

your model (we have just one type, Part)

• Pull-down lists activated as you select fields

• Our only edit – Initial Picture for animation

 (^) We picked Picture.Blue Ball from the default list

The Process Flowchart Module (cont’d.)

• Logic area – what happens to entities here  (^) Action - (^) Seize Delay Release – entity Seizes some number of units of a Resource (maybe after a wait in queue), Delay itself there for the processing time, then Release the units of the Resource it had Seized – we chose this option - (^) Could just Delay entity (red traffic light) – no Resources or queueing - (^) Could also Seize Delay (no Release … Release downstream) or Delay Release (if Resource had been Seized upstream) - (^) Priority for seizing – lower numbers mean higher priority - (^) Different Action choices could allow stringing together several Process modules for modeling flexibility  (^) Resources – define Resource(s) to be seized, released - (^) Double-click on row to open subdialog - (^) Define Resource Name, number of units to be Seized/Released - (^) Several Resources present (Add) – entities must first Seize all

The Process Flowchart Module (cont’d.)

• Delay Type – choice of probability distributions,

constant or general Expression (more later …)

• Units – time units for the delay

• Allocation – how to “charge” delay in costing

(more later …)

• Prompts on next line – change depending on

choice of Delay Type – specify numerical parameters involved

• Can also edit in spreadsheet view

 (^) Subdialogs (e.g., Resource here) become secondary spreadsheets that pop up, must be closed