1. Powersim Studio 2003
User’s Guide

3. Powersim Studio 2003
User's Guide
by Powersim Software AS
The Business Simulation Company
Sandbrugt. 5-7 ● PO Box 3961, Dreggen ● N-5835 Bergen ● Norway
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4. Copyright © 1997 – 2003 by Powersim Software AS. All rights reserved.
No portion of the contents of this publication may be reproduced or transmitted in any form or by
any means without the express written permission of Powersim Software AS.
Trademark, service mark, and copyright acknowledgements appear in the Powersim Studio 2003
Reference Manual.
The Software License Agreement and Limited Warranty also appears in the Appendix of the
Reference Manual.
We have done our best to ensure that the material found in this publication is both useful and
accurate. However, please be aware that errors may exist in this publication, and that neither the
authors nor Powersim Software AS make any guarantees concerning the accuracy of the
information found here or in the use to which it may be put.
Mention of third-party products is for informational purposes only and constitutes neither an
endorsement nor a recommendation. Powersim Software AS assumes no responsibility of models
created using software marketed by Powersim Software AS.
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5. Foreword
Making business decisions
Today, business simulations are used in making business decisions. Faced with a decision on where
to build natural gas storage containers, and how big to build these containers, one oil company used
Powersim to build a simulation of the wells, the pipelines, and the markets. Once the simulation
was built, decision-makers at the oil company could try different storage container scenarios. The
consequences of the different scenarios could be understood in a risk-free environment before any
investments in construction of storage containers were made.
Business simulations are also used in explaining business decisions to others in the organizations.
For example, a major telecommunications company saw many of their competitors making risky
forays into interactive television, adventures that were garnering much publicity. It was not enough
to just focus on their core business; they also had to explain to the employees why investing in
interactive TV and similar ventures were bad business decisions. This telecommunications
company built an interactive simulation of how they perceived their business. Over 1200
employees used this simulation in a series of management training workshops, where employees
had an opportunity to run the simulated business and make investment decisions. The employees
gained new appreciation for the corporate strategy, and a better understanding of how the thought
leaders in their organization saw the dynamics of the next few years unfolding.
Both of these simulation success stories were achieved using Powersim software. In each case a
team of modelers and thought leaders from the business collaborated to build a custom model of
the business problem. The models contained enough of the important details and complexities of
the real world situation to be useful and believable.
Business simulations more common
The use of simulation in business is not yet an everyday occurrence, but it is spreading. In 1990,
both of these examples would have been quite unusual. Although simulation technology was well
understood by 1990, and the cost of the necessary software tools had become modest, very few
business decisions were supported by simulating the consequences before taking action. It simply
was not part of standard business practice. Now things are changing, and the use of business
simulation is becoming more common.
At Powersim Software AS, we are committed to supporting the emerging practice of business
simulation. We appreciate that the process of business decision-making is different from that of
decision-making in public policy. Our tools are focused on modeling business problems, not on
public policy or academic issues.
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6. From models to simulators
Why this sudden change in business practices? Business models are not substantially easier to build
now than they were at the before. Nor has there been a watershed event that has made the business
community suddenly more receptive to simulation. From the viewpoint of us in the business
modeling community, building simulation models for years, the change is welcome, but a little
mysterious. However, from the viewpoint of our business customers, there has been a technology
revolution of sorts. Once a model is built, it is easy to build a high-quality user interface around it,
and turn it into a business simulator. Anyone can run the business simulator, trying different
decision scenarios and understanding the resultant behaviors.
The joy of simulators
Who has the time and interest to play with a business simulator? Everyone seems to make time.
Some commercial simulators – like SimCity and The Sims – are so much fun to play that they are
sold as entertainment. While few business executives might admit to playing games, they will
gladly play with a custom business simulator, crafted to model an aspect of their current
environment. One very serious senior executive remarked that playing a custom simulator of his
telecommunications company was "a joyful experience." Another senior executive at the same
organization spent 10 hours over two evenings playing the simulation.
Crafting a joyful experience can mean the difference between 4 people understanding your model
and its implications--and 1000 people understanding it. And joy is impossible if casual users must
struggle with arcane controls, obscure commands, or cryptic numerical displays.
The value of simulators
Joy alone is not enough in a business context: there must also be value. What is the value of
business managers playing a business simulator? Do the people playing the simulation make better
decisions? Do they learn more about the world in which they must succeed?
For many years, we in the business modeling community have approached the problem of creating
value by teaching business people a new way of thinking. We have taught them the basics of
building models, and when that was too difficult, we taught "systems thinking," how to see their
world the way a modeler might see it. Systems thinking is undoubtedly valuable for anyone who
chooses to undergo the education--but it has certain shortcomings as a discipline that can be put to
use within a business. Some people will never learn how to think systemically; and in fact, business
people expect something less abstract and more tangible for their investments in time and money.
Provide them a simulated experience – with their new situation, in their industry, in their context,
with their assets and constraints – and you’ve empowered them to solve existing problems, and
avoid potential ones.
Our goal at Powersim Software AS is to support you in "publishing" custom models of your
business, making them available to everyone who might need to know or care. And there are a lot
of people who might care: existing employees, new recruits, suppliers, distributors, customers, and
investors.
Learning from simulators
By playing a simulator, by trying different combinations of decisions, a business manager can
understand a simulation in a kind of kinesthetic way. Just as you don’t need to understand the
physics of skiing to learn how to ski, in the same way it is possible to play a simulation model and
learn the dynamics of a business situation – without understanding the details of the underlying
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7. mechanics. Through simulation, a businessperson can thus acquire experience not only without
"field" work, but also without necessarily understanding details of the model behind it.
Powersim Studio supports two approaches to building business simulators: building a simulator
within Powersim itself, and building a simulator in a general-purpose, interface-building language
and using Powersim as a simulation engine through the available Powersim Studio Software
Development Kit (SDK).
Within Powersim Studio, a modeler can use a host of interface objects. You can present the state of
the simulation by a gauge, by a graph of an array, and by many other means. You may also
program events that will occur when certain situations occur in your simulation.
As more and more organizations build business simulators to understand their world, and
communicate it to others within their organization and outside, your job will become more exciting
and more important. We at Powersim are committed to supporting you in your efforts to build
business simulators.
Good luck with your purchase of Powersim Studio 2003!
The Powersim Software Development Team
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9. Table of Contents
Foreword............................................................................................................................ 5
Table of Contents .............................................................................................................. 9
Getting Started ................................................................................................................ 25
What’s new in Powersim Studio 2003? ......................................................................... 28
Introduction to System Dynamics.................................................................................. 32
The tools and rules of System Dynamics ............................................................ 35
Building the models ............................................................................................ 41
Building blocks in Powersim Studio................................................................... 44
Creating a model ................................................................................................. 47
Importing models from Powersim Constructor 2.51 ................................................... 48
About variable conversion .................................................................................. 48
About diagram conversion .................................................................................. 51
About simulation conversion .............................................................................. 52
Convert the ASSIGN function ............................................................................ 53
Convert constrained expressions......................................................................... 56
Convert the SHIFT functions .............................................................................. 57
Convert the LIMIT functions .............................................................................. 61
Working with help in Powersim Studio ........................................................................ 63
Topic layout ........................................................................................................ 63
The help window................................................................................................. 64
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10. Customize the help window ................................................................................ 65
Hide or show the navigation pane....................................................................... 66
Use the Powersim Learning Lab ......................................................................... 66
Find a help topic.................................................................................................. 66
Copy a help topic ................................................................................................ 67
Print the current help topic.................................................................................. 67
Use the favorites tab............................................................................................ 67
Find information with full-text search ................................................................ 67
Get help in a dialog box ...................................................................................... 68
Highlight words in searched topics ..................................................................... 68
Work with Powersim Studio .......................................................................................... 69
Components and simulations .............................................................................. 70
Work with a simulation project ..................................................................................... 72
Create a simulation project.................................................................................. 72
Create project documentation ............................................................................. 72
Open an existing project ..................................................................................... 73
Save a simulation project .................................................................................... 73
Create a backup project....................................................................................... 74
Restore a backup project ..................................................................................... 74
Compact a simulation project.............................................................................. 74
View project documentation ............................................................................... 75
Show and edit project information...................................................................... 75
Show recently opened projects............................................................................ 75
View project statistics ......................................................................................... 76
Work with levels of protection............................................................................ 76
Levels of protection ............................................................................................ 76
Protect the simulation project.............................................................................. 77
Unprotect the simulation project......................................................................... 77
Change level of protection .................................................................................. 77
Redo an operation ............................................................................................... 77
Undo an operation............................................................................................... 77
Work with windows and diagrams................................................................................ 79
View equations.................................................................................................... 80
Create a new diagram sheet................................................................................. 80
Select sheets ........................................................................................................ 80
Move sheets......................................................................................................... 81
Exclude a sheet.................................................................................................... 81
Include a sheet..................................................................................................... 81
Rename a sheet.................................................................................................... 81
Delete a sheet ...................................................................................................... 82
Adjust columns in treeviews ............................................................................... 82
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11. Select entries in treeviews................................................................................... 82
Switch between hierarchical and flat view in treeviews ..................................... 82
Organize windows............................................................................................... 83
Save window position ......................................................................................... 83
Open a new window for the active component ................................................... 84
Close the active window ..................................................................................... 84
Close all windows ............................................................................................... 85
The Project Window ........................................................................................... 85
The Status Bar..................................................................................................... 85
Dock the Project Window ................................................................................... 86
Create a folder in the Project Window................................................................ 86
Show or hide the Project Window ...................................................................... 86
Working with toolbars and keyboard shortcuts................................................... 86
Select a persistent tool......................................................................................... 87
Move or dock a toolbar ....................................................................................... 87
Show or hide a toolbar ........................................................................................ 87
Diagram commands ............................................................................................ 88
Format commands............................................................................................... 91
Layout commands ............................................................................................... 93
Simulation commands......................................................................................... 94
Standard commands ............................................................................................ 96
Symbol commands.............................................................................................. 98
Presentation commands....................................................................................... 99
View commands................................................................................................ 101
Constructor keyboard shortcuts and modifiers ................................................. 103
Studio keyboard shortcuts ................................................................................. 105
Working with components ........................................................................................... 107
About simulations ............................................................................................. 108
About private and shared diagrams................................................................... 108
Create a new component ................................................................................... 109
Rename a component ........................................................................................ 109
Add a simulation to the component .................................................................. 109
Open a simulation’s diagram window............................................................... 110
Create a submodel from a component............................................................... 110
Delete a component........................................................................................... 113
Constructor and Interaction Diagrams....................................................................... 114
Work with Constructor diagrams ............................................................................... 116
Diagrams and models........................................................................................ 116
The building blocks of a Constructor diagram.................................................. 117
Constructor diagram symbols ........................................................................... 118
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12. Diagram errors and inconsistencies .................................................................. 120
Adding controls and auto reports to a diagram ................................................. 121
The stacking order of diagram objects .............................................................. 122
Toggle between Design and User mode............................................................ 123
Change stacking order of objects ...................................................................... 123
Working with variables in Constructor diagrams ..................................................... 124
About snapshots ................................................................................................ 125
Create a level..................................................................................................... 125
Create an auxiliary ............................................................................................ 126
Create a constant ............................................................................................... 126
Create a flow rate variable ................................................................................ 127
Create a snapshot .............................................................................................. 127
Go to original from a snapshot.......................................................................... 128
Make original from a snapshot.......................................................................... 128
Create a reservoir .............................................................................................. 128
Name and rename a variable ............................................................................. 129
Resize a basic variable symbol ......................................................................... 130
Scale a basic variable symbol ........................................................................... 130
Work with links and flows............................................................................................ 131
Keyboard modifiers when working with links and flows ................................. 131
Change the shape of a link ................................................................................ 132
Create a link ...................................................................................................... 133
Create an initialization link ............................................................................... 133
Create a delayed link......................................................................................... 133
Delete a link ...................................................................................................... 134
Change the shape of a flow ............................................................................... 134
Create a flow ..................................................................................................... 135
Create a flow without a rate variable ................................................................ 135
Disconnect the head or tail of a flow ................................................................ 136
Reconnect a flow to a different level ................................................................ 136
Detach a flow rate variable ............................................................................... 136
Attach a flow rate variable ................................................................................ 136
Move the valve of a flow .................................................................................. 137
Change the rate variable of a flow .................................................................... 137
Delete a rate variable......................................................................................... 138
Delete a flow ..................................................................................................... 138
Build hierarchical models............................................................................................. 139
About submodels............................................................................................... 140
About submodel diagrams ................................................................................ 142
About public variables ...................................................................................... 142
About child variables in auxiliaries, levels, and constants................................ 143
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13. Consistency rules for submodel diagrams......................................................... 144
Create a submodel ............................................................................................. 146
Create a submodel from a component............................................................... 146
Include child variables in parent diagrams........................................................ 147
Open a diagram for a variable........................................................................... 148
Create links to or from a submodel ................................................................... 148
Create flows to or from a submodel.................................................................. 149
Create an anonymous flow................................................................................ 151
Work with diagram editing .......................................................................................... 152
Drag and drop operations .................................................................................. 153
Include a model variable in a diagram .............................................................. 154
Exclude a model variable from a diagram ........................................................ 154
Delete a variable................................................................................................ 154
Link variables to Powersim Controls................................................................ 155
Copy and paste an object .................................................................................. 156
Cut and paste an object ..................................................................................... 156
Copy an area as a picture .................................................................................. 156
Paste from Windows Clipboard ........................................................................ 157
Select objects..................................................................................................... 157
Select multiple objects ...................................................................................... 158
Select dominant object ...................................................................................... 158
Move an object.................................................................................................. 158
Position an object by coordinates...................................................................... 159
Delete diagram objects...................................................................................... 159
Work with nodes, segments and lines.......................................................................... 160
Types of nodes .................................................................................................. 161
Types of segments............................................................................................. 161
Add a node ........................................................................................................ 162
Change the type of a node................................................................................. 162
Change the type of all nodes of a line ............................................................... 162
Delete a node..................................................................................................... 162
Change the type of a segment ........................................................................... 163
Change the type of all segments of a line ......................................................... 163
Drag a line into a new shape ............................................................................. 163
Make an elbowed line ....................................................................................... 163
Change a line into a single curved segment ...................................................... 164
Change a line into a single straight segment ..................................................... 164
Work with the Details Window.................................................................................... 166
Show and hide the Details Window .................................................................. 167
Display the Detail Window at top..................................................................... 167
Auto-synchronize Details with diagram............................................................ 168
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14. Work with auto reports ................................................................................................ 170
Show a number auto report ............................................................................... 170
Show a time graph auto report .......................................................................... 171
Hide an auto report............................................................................................ 171
Unhide an auto report........................................................................................ 172
Change type of auto report................................................................................ 172
Move and position an auto report...................................................................... 172
Delete an auto report ......................................................................................... 173
Size an auto report............................................................................................. 173
Working with grids and guides.................................................................................... 173
Show or hide rulers ........................................................................................... 174
Turn the display of grid on/off .......................................................................... 174
Turn the display of guides on/off ...................................................................... 175
Turn snap to regular grid on/off ........................................................................ 175
Turn snap to the radial grid on/off .................................................................... 175
Turn snap to guides on/off ................................................................................ 175
Change grid settings.......................................................................................... 176
Change guide settings ....................................................................................... 176
Insert guides ...................................................................................................... 177
Move guides...................................................................................................... 177
Delete guides..................................................................................................... 178
Work with object properties ........................................................................................ 179
Format several objects in one operation............................................................ 179
Format text ........................................................................................................ 180
Format the diagram background ....................................................................... 180
Use picture fills for objects ............................................................................... 180
Align diagram objects ....................................................................................... 181
Rotate diagram objects...................................................................................... 181
Space diagram objects....................................................................................... 182
Make diagram objects the same size ................................................................. 182
Position objects ................................................................................................. 183
Resize an object ................................................................................................ 183
Resize a multiple selection................................................................................ 183
Change line style and color ............................................................................... 184
Change object color and shape.......................................................................... 184
Work with freeforms, frames, hyperlinks and bookmarks ....................................... 186
About bookmarks.............................................................................................. 186
About hyperlinks............................................................................................... 187
Add a frame....................................................................................................... 188
Add text to a frame............................................................................................ 188
Add a picture to a frame.................................................................................... 189
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15. Add a bookmark................................................................................................ 189
Add a hyperlink................................................................................................. 190
Create hyperlinks without text .......................................................................... 191
Open a hyperlink............................................................................................... 191
Resize a frame to fit a picture ........................................................................... 191
Use a frame as background ............................................................................... 192
Select a transparent frame ................................................................................. 192
Draw a freeform line ......................................................................................... 192
Reshape a freeform ........................................................................................... 193
Create image maps ............................................................................................ 193
Change arrowheads and –tails on freeform lines .............................................. 194
Change the order of freeforms .......................................................................... 194
Delete a hyperlink ............................................................................................. 194
Delete a bookmark195
Work with zoom ............................................................................................................ 196
Zoom a diagram ................................................................................................ 196
Zoom a selection ............................................................................................... 196
Zoom to fit diagram in view.............................................................................. 197
Work with simulations.................................................................................................. 198
About simulation state and history.................................................................... 199
The calendars .................................................................................................... 199
Simulations without time units ......................................................................... 200
Set preferred time units ..................................................................................... 201
Set simulation times .......................................................................................... 202
Change the calendar .......................................................................................... 203
Select available calendars ................................................................................. 203
Set start time and stop time ............................................................................... 204
Set the time step ................................................................................................ 204
Set the simulation speed.................................................................................... 204
Autoscale variables when simulation is paused ................................................ 205
Keep history for all variables ............................................................................ 205
Save simulation state with project..................................................................... 205
Set the run count ............................................................................................... 206
Turn o/off time units for simulation time.......................................................... 206
Integration methods........................................................................................... 207
About integration .............................................................................................. 208
Integration methods: Known quirks.................................................................. 209
The Euler integration method............................................................................ 209
The Runge-Kutta integration methods .............................................................. 210
Set integration order.......................................................................................... 211
Start and stop a simulation ................................................................................ 211
Play a simulation stepwise ................................................................................ 211
Reset a simulation ............................................................................................. 212
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16. Add cue points to the simulation run ................................................................ 212
Go to a cue point in the simulation run ............................................................. 212
Manually autoscale all variables ....................................................................... 213
Restore permanent variables ............................................................................. 213
About runs and reference data........................................................................... 213
Saving a simulation run..................................................................................... 214
Activating a saved run....................................................................................... 215
Rename a simulation run................................................................................... 215
Exporting a simulation run................................................................................ 215
Importing a simulation run................................................................................ 216
Make a simulation run visible in Presentation Mode........................................ 216
Enter documentation for a simulation run......................................................... 217
Delete a simulation run ..................................................................................... 217
Select reference data ......................................................................................... 217
About the report window and intervals............................................................. 218
Set up major and minor time intervals .............................................................. 218
Set up report window ........................................................................................ 219
Working with Units of Measurement .......................................................................... 220
About unit operations........................................................................................ 221
Properties, Identifiers, and pre-defined units .................................................... 222
Create a model without units............................................................................. 227
Available time units in the project .................................................................... 227
Add a global unit............................................................................................... 228
Add a local unit ................................................................................................. 228
Add currency units ............................................................................................ 229
Add standard units ............................................................................................ 230
Define an atomic unit ........................................................................................ 230
Define a derived normal unit............................................................................. 230
Define a derived point unit................................................................................ 231
Specify a unit for a level ................................................................................... 232
Specify a unit for a constant.............................................................................. 232
Specify a unit for an auxiliary........................................................................... 233
Include units in variable expressions ................................................................ 233
Explicitly select unit for an expression ............................................................. 234
Create unitless variable expressions.................................................................. 235
Delete a global unit ........................................................................................... 235
Delete a local unit ............................................................................................. 236
Working with variable definitions............................................................................... 237
Variable properties and options ........................................................................ 238
About permanent variables ............................................................................... 241
About reservoirs................................................................................................ 241
Variable definition examples ............................................................................ 243
About continuous flows .................................................................................... 248
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17. About discrete flows ......................................................................................... 249
About logical flows........................................................................................... 251
Flow function examples .................................................................................... 252
About circular definitions ................................................................................. 260
About the function wizard................................................................................. 261
About value formatting ..................................................................................... 262
Adding comments to definitions ....................................................................... 262
Define a variable on the property pages............................................................ 263
Define a variable in the name box..................................................................... 263
Define variable in the Equations View ............................................................. 264
Change variable type......................................................................................... 264
Define flow equations for a level ...................................................................... 264
Formatting variable definitions ......................................................................... 265
Insert a function in a definition ......................................................................... 265
Insert range name for a dimension .................................................................... 266
Insert unit name................................................................................................. 266
Insert variable name in a definition................................................................... 266
Set array dimensions from the Definition property page .................................. 267
Set unit of measurement.................................................................................... 267
Set data type for a variable................................................................................ 268
Insert a function expression with the Function Wizard..................................... 268
View the current value of a variable ................................................................. 269
Write documentation for a variable................................................................... 269
Customize the appearance of definitions .......................................................... 269
About hierarchical models ................................................................................ 270
Private and public variables .............................................................................. 271
Hierarchical syntax ........................................................................................... 273
Monitor the flows of a level .............................................................................. 275
Hierarchical models: Examples......................................................................... 276
Working with the Equations View............................................................................... 281
Create a variable in the Equations View ........................................................... 281
Create a link in the Equations View.................................................................. 282
Define a variable ............................................................................................... 282
Create a flow in the Equations View................................................................. 282
Reverse a flow in the Equations View .............................................................. 283
Change variable type in the Equations View .................................................... 283
Delete an object................................................................................................. 283
Working with Range and Index Variables ................................................................. 285
Types of ranges ................................................................................................. 285
About index variables ....................................................................................... 286
Add a global range ............................................................................................ 288
Add a local range .............................................................................................. 288
Create an index variable.................................................................................... 288
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18. Define an enumerated range.............................................................................. 288
Rename range elements .................................................................................... 289
Define an enumerated subrange ........................................................................ 289
Define a numerical subrange............................................................................. 290
Specify a global range for a variable................................................................. 290
Specify a local range for a variable................................................................... 291
Explicitly select a range for a variable .............................................................. 291
Delete a global range or index variable............................................................. 291
Delete a local range or index variable............................................................... 292
Work with summary types ........................................................................................... 293
Summary types and discrete variables .............................................................. 294
Working with arrays..................................................................................................... 297
Why use arrays? ................................................................................................ 297
Create layered models using arrays................................................................... 299
Create queues using arrays................................................................................ 299
Array syntax...................................................................................................... 300
Create arrays ..................................................................................................... 301
Create arrays using ranges and subranges......................................................... 302
Build arrays element by element....................................................................... 303
Build arrays using the FOR function ................................................................ 303
Build arrays using the CONCAT function........................................................ 305
Index arrays....................................................................................................... 305
Index arrays using the INDEX function............................................................ 306
Use basic variables as index variables .............................................................. 307
Index arrays using ranges and subranges .......................................................... 307
Redimension arrays........................................................................................... 308
About Powersim Controls ............................................................................................ 310
Insert a control in your diagram ........................................................................ 311
Move a control .................................................................................................. 311
Use index variables in controls ......................................................................... 311
Delete a control ................................................................................................. 313
Toggle between Design and User Mode ........................................................... 313
Work with parameters.................................................................................................. 315
Add active run parameters to a control ............................................................. 315
Add reference run parameters to a control ........................................................ 316
Add simulation control parameters to a control ................................................ 316
Add index variable parameters to a control ...................................................... 317
Add parameters with summary types................................................................ 317
Adjust the scale of a parameter ......................................................................... 318
Remove parameters from a control ................................................................... 318
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19. Hide or show parameters in User Mode............................................................ 319
Change the input mode of a control .................................................................. 319
Formatting controls ...................................................................................................... 321
Axis formatting ................................................................................................. 321
The value axis and parameters with different units........................................... 322
Resize a control................................................................................................. 323
Format an axis................................................................................................... 323
Change position of an axis ................................................................................ 324
Change the orientation of text in controls ......................................................... 324
Show label for an axis ....................................................................................... 325
Change the scaling of the value axis ................................................................. 325
Customize the appearance of a control ............................................................. 325
Change position of the unit label ...................................................................... 326
Show and format the title .................................................................................. 326
About field codes ........................................................................................................... 327
Field codes and languages................................................................................. 329
Legends and parameter titles when using field codes ....................................... 330
Define a field code ............................................................................................ 331
Work with the Chart Control ...................................................................................... 333
Format the graphs.............................................................................................. 334
Change the graph type of a parameter............................................................... 334
Change the order of parameters ........................................................................ 335
Hide parameters from the chart......................................................................... 335
Show hidden parameters in the chart ................................................................ 335
Format the chart area......................................................................................... 336
Show gridlines................................................................................................... 336
Toggle on/off the legend for the chart............................................................... 336
Presenting a set of scalar variables in a Chart Control...................................... 337
Use the Chart Control as an input object .......................................................... 337
Work with the Gauge Control ..................................................................................... 339
Examples of gauge formatting .......................................................................... 339
Gauge dial properties ........................................................................................ 341
Gauge needle properties.................................................................................... 343
Format the gauge dial........................................................................................ 344
Format the gauge needle ................................................................................... 345
Format the gauge hub........................................................................................ 346
Show or hide the gauge hub .............................................................................. 346
Rotate the Gauge Control.................................................................................. 347
Use the Gauge Control as an input control ....................................................... 347
Create a gauge with sectors............................................................................... 348
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20. Work with the Slider Bar Control............................................................................... 349
Change the orientation of the slider bar ............................................................ 349
Work with the Switch Control ..................................................................................... 350
Create a button .................................................................................................. 351
Create a check button ........................................................................................ 351
Create radio buttons .......................................................................................... 352
Create a list box................................................................................................. 353
Create a combo box........................................................................................... 354
Create a static text object .................................................................................. 354
Use the Switch Control to select strategy ......................................................... 355
Work with the Table Control....................................................................................... 357
Add an Array to the Table Control ................................................................... 357
Add or insert a column in the Table Control..................................................... 358
Add or insert a row in the Table Control .......................................................... 358
Display text in a cell.......................................................................................... 358
Display a variable’s name in a cell ................................................................... 359
Display a variable’s value in a cell ................................................................... 359
Change the height of rows and width of columns............................................. 360
Delete a column in the Table Control ............................................................... 360
Delete a Row in the Table Control.................................................................... 360
Use the Table Control as an input object .......................................................... 360
Work with the Time Graph Control ........................................................................... 362
Format the graphs.............................................................................................. 362
Format the time axis in the Time Graph Control .............................................. 363
Use parameters with summary types in the Time Graph Control ..................... 365
Change the order of parameters ........................................................................ 365
Change the graph type of a parameter............................................................... 366
Hide parameters from the Time Graph ............................................................. 366
Show hidden parameters in the Time Graph..................................................... 367
Show and export the history of a parameter...................................................... 367
Format the graph area ....................................................................................... 367
Show gridlines................................................................................................... 368
Toggle on/off the legend for the Time Graph ................................................... 368
Create a scrolling Time Graph .......................................................................... 368
Work with the Time Table Control............................................................................. 370
Format the time display in the Time Table Control .......................................... 370
Change the order of parameters ........................................................................ 371
Change the reporting interval in the Time Table Control ................................. 371
Change the orientation of the Time Table......................................................... 372
Hide parameters from the Time Table Control ................................................. 372
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21. Work with Risk Assessment......................................................................................... 373
About Risk Assessment .................................................................................... 374
The Risk Assessment process ........................................................................... 375
How to assess risk ............................................................................................. 375
The Monte Carlo sampling method................................................................... 376
The Latin Hypercube sampling method ............................................................ 376
Select and define a sampling method................................................................ 377
Working with Risk Assessment variables......................................................... 377
Probability distributions.................................................................................... 378
Select variables for Risk Assessment................................................................ 379
Define an assumption with a probability distribution ....................................... 379
Define an assumption with a fixed value .......................................................... 380
Specify an effect variable.................................................................................. 381
Delete a Risk Assessment variable ................................................................... 381
Presenting Risk Assessment results .................................................................. 381
Create a high-low chart ..................................................................................... 384
Create a high-low table ..................................................................................... 385
Create a histogram ............................................................................................ 386
Datasets in Powersim Studio ........................................................................................ 388
About datasets ................................................................................................... 388
Dataset overview............................................................................................... 389
About dataset variables ..................................................................................... 390
About dataset variable dimensions.................................................................... 390
About history in datasets................................................................................... 391
About transfers in datasets ................................................................................ 391
Create a datasets................................................................................................ 392
Connect a dataset to a component..................................................................... 393
Create dataset variables by drag and drop......................................................... 393
Create dataset variables manually..................................................................... 394
Connect model and dataset variables ................................................................ 395
Set the transfer directions for model and dataset variables ............................... 396
Set all the dataset variables to the same dimensions......................................... 397
Set the summary type for a dataset variable...................................................... 398
Set the dimension of a dataset variable ............................................................. 398
Disconnect dataset and model variables ........................................................... 399
Disconnect a dataset from a simulation ............................................................ 399
Rename a variable in the dataset....................................................................... 399
Rename a dataset............................................................................................... 399
Rename a dataset in the Co-models View......................................................... 400
Delete dataset variables..................................................................................... 400
Delete a dataset ................................................................................................. 400
Load history from a dataset............................................................................... 400
Save a dataset .................................................................................................... 401
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22. Edit the history of a dataset variable ................................................................. 401
Import the history of a dataset variable............................................................. 402
Export the history of a dataset variable............................................................. 403
The Studio Dataset ........................................................................................................ 403
About the Studio Dataset .................................................................................. 403
Set period information for the Studio Dataset................................................... 404
Working with the spreadsheet datset .......................................................................... 405
The inner workings of the SpreadsheetDataset ................................................. 405
Set sampling times for the dataset..................................................................... 407
Connect the dataset to a spreadsheet ................................................................. 407
Control spreadsheet layout................................................................................ 408
Define starting cell of the spreadsheet .............................................................. 409
Format a spreadsheet for transfer to a model variable ...................................... 410
Format array dimensions................................................................................... 410
Sort the order of variables in the spreadsheet ................................................... 411
Synchronize the component and the spreadsheet.............................................. 411
Update the spreadsheet with values only .......................................................... 412
Use the dataset without saving the spreadsheet ................................................ 412
Ensure valid data from spreadsheet................................................................... 413
Use names for cells, sheets, or file that change with run number ..................... 413
Use a spreadsheet template ............................................................................... 414
Use the dataset to transfer immediate behavior ................................................ 414
Use the dataset to transfer behavior over time .................................................. 414
Create a bi-directional transfer for variables..................................................... 415
Transfer behavior from a spreadsheet to a model variable ............................... 415
Transfer behavior from a model variable to a spreadsheet ............................... 416
Interpolate transferred data between data points............................................... 416
Transfer data at given times in the spreadsheet................................................. 417
Transfer all data at the end of the simulation .................................................... 418
Work with the SEM Dataset ........................................................................................ 419
How the SEM Dataset works ............................................................................ 420
Connection details for the SEM Dataset ........................................................... 422
Mapping time characteristics in SEM to simulation time ................................. 424
Time translations in the SEM Dataset............................................................... 426
Ranges and units in the SEM Dataset ............................................................... 427
Work offline with the SEM Dataset.................................................................. 428
How to prepare SEM-BPS for the SEM Dataset............................................... 429
Define a SEM Dataset....................................................................................... 433
Synchronize a SEM Dataset with SEM ............................................................ 434
Using summary types for key figures ............................................................... 434
Load and save date using the SEM Dataset ...................................................... 434
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23. Set and lock packages in the SEM Dataset ....................................................... 435
Set and lock versions in the SEM Dataset ........................................................ 436
Allow the simulation user to specify package and version ............................... 436
Disconnect Powersim Studio from SEM .......................................................... 437
Utilizing modes in Studio.............................................................................................. 438
About the Presentation Mode............................................................................ 438
The difference between User and Presentation Mode....................................... 440
Create a simulator for Presentation Mode......................................................... 440
Toggle between Design and User Mode ........................................................... 441
Switch to Presentation Mode ............................................................................ 441
Switch to Design Mode from Presentation Mode ............................................. 442
Start Project in Presentation Mode.................................................................... 442
Specify the Presentation of a project................................................................. 442
Navigate in Presentation Mode ......................................................................... 442
Add and view project documentation in Presentation Mode ............................ 443
Use game files in Presentation Mode................................................................ 443
Protect your project in Presentation Mode........................................................ 444
The Presentation Mode toolbar ......................................................................... 444
Work with Languages................................................................................................... 446
Automatic language selection ........................................................................... 447
The Neutral language ........................................................................................ 448
The Common languages.................................................................................... 449
Set language for a project.................................................................................. 449
Explicitly set language for a view..................................................................... 449
Toggle language prefix on/off........................................................................... 449
Translate a project............................................................................................. 450
Finding variables........................................................................................................... 452
About problematic variables ............................................................................. 452
Find problematic variables................................................................................ 453
Find undefined variables ................................................................................... 454
Find variables by definition .............................................................................. 454
Find variables defined by the selected variable ................................................ 455
Go to a variable ................................................................................................. 455
Go to next variable............................................................................................ 455
Working with events ..................................................................................................... 456
Types of event actions....................................................................................... 456
Event properties ................................................................................................ 458
Add an event ..................................................................................................... 459
Define an event ................................................................................................. 459
Change event order ........................................................................................... 460
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24. Add an action to an event.................................................................................. 460
Change action order .......................................................................................... 461
Delete an action................................................................................................. 461
Delete an event.................................................................................................. 461
Printing a simulation project ....................................................................................... 462
Syntax for printed equations ............................................................................. 462
Print one or more diagrams ............................................................................... 463
Print equations................................................................................................... 464
Set page margins ............................................................................................... 464
Set page orientation........................................................................................... 465
Set page scaling................................................................................................. 465
Set paper size .................................................................................................... 465
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25. Getting Started in Powersim Studio
If you are new to Powersim Studio, the following steps will help you get started creating simulation
models. If you want more detailed instructions on how to create models and simulations, please refer
to the tutorials available in the Learning Lab.
Although the list below gives a linear view of the modelling process, you will soon experience that it
is rather an iterative process where you revisit previous stages many times before you have finished
the model. The steps below are only meant as an overview of the steps required.
1. Create a new simulation project
Powersim Studio is always opened with a new project (unless you started Studio by
opening an existing simulation project, that is). The project contains one component by
default, and you can add as many components that you need. All components and
views are available in the Project Window that you can see on the left of the
application. Each component can contain many simulations, with various simulation
settings. Each component has one simulation by default.
2. Create units of measurement
In the real world, most quantities are expressed using units of measurement. This is
also the case in Studio, where all variables will usually have a unit. To be able to
define the variables, you will therefore have to create the units first. You can always go
back and create more units as you find necessary!
Tip! It is easiest to create and use global units, which are available to all the
components in the project.
3. Create variables, links, and flows
You create variables and link them together using links and flows in Constructor
diagrams. The diagrams offer a good visualization of your model, and it is easy to see
the feedback loops that make up the system.
Tip! You can create as many diagrams you want per component. All variables
do not have to be part of each diagram. You can see all your variables in the
Details Window or the Equations View.
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26. 4. Define variables and flows
Once you have created the variables, it's time to define them. This is done in the
Definitions property page, available when you double-click the variable (or hit
ALT+ENTER). The variable definition expresses how the variable relates to other
variables in the model. Flows are defined by the flow rate that controls them, and they
are added to the level according to the level's flow definition.
Tip! You will probably often create variables and define them at the same time,
performing this and the previous step simultaneously.
Note! You must always make sure that (continuous) flow rates have a "rate"
unit, that is, it has to have a unit compatible with the level's unit divided by time.
5. Set up the simulation
Before you can run your simulation, you must specify the simulation settings to be
used by the component. The simulation setup is essential to make your simulation
behave the way that you want to. The time horizon of a simulation will vary with the
system your are studying. If you are studying a human population, as an example, your
time horizon will probably be about a century or two, with a resolution of a year or
two. If you are studying the life cycle of a product, however, you are more likely to
require a time horizon of a few years, with weeks or months as the time step.
6. Create data in- and output objects
It is not very useful to run a simulation unless you can view the results of your
simulation while it runs. You can use auto reports and controls to display the
simulation results. You have time graphs, charts, tables, slider bars, and gauges at your
disposal for displaying simulation results.
In many cases you also need to provide input for your constants while the simulation
runs. This is also achieved by the use of controls. You can create buttons or sliders as
tools for data input.
7. Add navigation capabilities and documentation
When your simulation behaves the way you want to, it's time for the final touch. Add
navigation to your simulation by the use of hyperlinks and bookmarks, and add
documentation to your model diagrams using freeforms and frames with text. If you
need to further document your simulation, you can create your own help system in
HTML that can be started from the project.
8. Create and save reference data
It is often useful to be able to compare a simulation run to data from other simulation
runs. This is possible in Studio by using reference parameters and reference data. You
can also save a simulation run and activate it again later.
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27. 9. Set up the Presentation Mode
Finally, you can use the Presentation Mode to present the simulator interface you have
created to the user. The Presentation Mode removes all the development-related tools
and buttons, and displays only the simulator itself.
You can use the Presentation Mode as a "simulation browser," which makes your simulation easily
available for your end-users.
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28. What's New in Powersim Studio 2003?
Powersim Studio 2003 contains a range of new features and functionality that makes your simulations
easier to create and more powerful to analyse. The most important features are described below. You
can also read a brief listing of the new features and functionality.
Risk Assessment
Studio 2003 now includes the Risk Assessment task — one of the four tasks earlier available in
Powersim Solver. Factors that are external to your own organization, such as the inflation rate, or
other values that are difficult to determine, represent risk factors if they seriously affect the results
from your simulation. Through the Risk Assessment task in Studio, you can now investigate how
changes in these assumptions affect your results. The result of such a simulation is the likelihood of
achieving a certain result. You can also use Risk Assessment to find variables that are leverage points
for improving performance.
The Risk Assessment task let you analyze the sensitivty of your model.
Hierarchical Models
With the introduction of model hierarchy, Powersim Studio 2003 allows you to divide your
simulation model into smaller submodels that hide away unnecessary implementation details. As each
submodel can contain its own diagram book, modelling these submodels is just as easy as creating
any other model. In addition, submodels can be created from components in any simulation project.
This makes the duplication of existing model structures extremely easy! Utilizing model hierarchy
allows you to make more abstract models, divide your model into subsections that are easier to
maintain and model, and start reusing model structures from project to project.
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29. Hierarchical models allow implementation details to be hidden inside submodels, making your
models easier to read and understand.
Improved simulation capabilities
While you in earlier version of Studio could only have one simulation for each component in your
simulation project, you can now add as many simulations as you wish. Each simulation will maintain
its own set of variable values, but the model structure will be identical between each simulation. A
change to the Shared Diagrams of the component will always be reflected in all simulations. By using
Private Diagrams, however, you can create diagrams that are unique to the simulation you are
working on.
Improvements have also been done to time series, where you are now allowed to record summary
information for periods. You can select between several summary types, such as average,
accumulated, max, min, etc.
Summary types enable you to present your simulation results summarized over a period. You can
display summaries in time graphs and time tables.
The improvements also include optimisations to simulation speed; new and better views for
equations, units, co-models, and ranges; and index variables.
New modelling features
The property pages for variable definitions are greatly improved and simplified, especially when
implementing large variable definition expressions. A new function, the VBFUNCTION, allows you
to create your own custom functions by programming them in VBScript.
Variable expression validation will now be performed when you edit a variable’s expression directly
in the diagram. You will also experience new user-friendliness when working with connectors (links
and flows) in Constructor diagrams, including more flexible point editing and useful messages on the
status bar while you work. Moving symbols between diagrams is also greatly improved.
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30. Anonymous flows allow you to gather all the flows from a submodel to another variable (level or
submodel) in your diagram in one common flow. An anonymous flow doesn’t have a flow rate,
obviously, but is a tidy way of showing how the flows run through your system.
When you have finished your simulation model and are working on documenting it, you can copy
model structures directly into your documents as graphics.
Other improvements and new features include improved delete and undo functionality; text search in
tree views, such as the Equations and Units views; the ability to organize your components and
datasets into your own folders; and much more.
Connectivity
Datasets have gone through a complete overhaul since Studio 2001. The user interfaces are now user-
friendlier, and now allow you to drag-and-drop variables from models into the datasets. The internal
workings of the datasets are also vastly improved. The new SAP® SEM dataset allows Powersim
Studio 2003 to run stand-alone and still connect to the SAP systems. You can also create multiple
instances of the dataset within Studio. The user interface for the Spreadsheet dataset is also
redesigned, and makes export and import of data from and to Microsoft® Excel a lot easier.
Studio 2003 introduces the new Studio Dataset, where you can record your time series to internal data
storages inside your simulation project. The Studio Dataset allows you to store data for later use; edit
time series that are used in the simulation manually; share simulation data between several
components; and more.
You have greater control over your external connections in Studio 2003 than in earlier versions of
Studio.
Presentation of simulations
The improvements to time series mentioned above, makes it easier than before to create interesting
presentations of simulation results. Combined with improvements in graphs and tables available in
Studio, this constitutes a powerful means of conveying your message. And you can now even copy
the history of a time graph to the Windows Clipboard!
Hyperlinks can now be made relative, allowing the same simulation interface to be used for all the
simulations within a component.
The introduction of index variables makes it possible for you to create controls that select between the
dimensions of array variables without having to implement this by the use of model variables.
Index variables can be used as parameters by input controls. You can in turn use the index variable to
index the parameter of output controls, greatly simplifying the user interface of complex simulations.
It is now easier to add parameters to your controls and you can even use controls to set simulation
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31. details, such as the start and stop times. Automatic detection of the states of the Switch control
simplifies the creation of buttons that control index variables and logical variables.
Other new features include field codes; rotation of tick labels; bar and step graphs in the Time Graph
control; the possibility to save and load external data (when using datasets) from Presentation Mode;
and much more.
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32. Introduction to System Dynamics
Simulations in Powersim Studio are based on system dynamics. System dynamics is a computer-
based simulation modeling methodology developed at the Massachusetts Institute of Technology
(MIT) in the 1950s as a tool for managers to analyze complex problems. Its primary audience is still
managers, although it has spread widely in academia, where professors and students use it to model
systems from every conceivable discipline ranging from history and literature to biology, physics, and
economics.
The word "dynamic" implies continuous change and that is what dynamic systems do - they
continuously change over time. Their position, or state, is not the same today as it was yesterday and
tomorrow it would have changed yet again.
Using system dynamics simulations allows us to see not just events, but also patterns of behavior over
time. The behavior of a system often arises out of the structure of the system itself, and behavior
usually changes over time. Sometimes the simulation looks backward, to historical results. At other
times it looks forward into the future, to predict possible future results.
Understanding patterns of behavior, instead of focusing on day-to-day events, can offer a radical
change in perspective. It shows how a system's own structure is the cause of its successes and failures.
This structure is represented by a series of causally linked relationships. The implication is that
decisions made within an organization have consequences, some of which are intentional and some
are not. Some of these consequences will be seen immediately while others might not be seen for
several years.
System dynamics simulations are good at communicating not just what might happen, but also why.
This is because system dynamics simulations are designed to correspond to what is, or might be
happening, in the real world.
Solving Problems
When confronted with problems or new situations, we can react to them in several possible ways. The
approach we select is based on prior experience and our knowledge of the problem at hand. As
humans, the most common approach to new problems and situations is to take them apart and
examine their pieces. We do this in the hope that by understanding the pieces we will also be able to
understand the entire problem or situation at hand. We are taught this method in our youth and it is
reinforced almost daily. This approach helps us manage the incredible amount of data, stress,
problems, and chaos that bombards us every day. If we didn't have this ability, all but the simplest
problems would appear overwhelming.
Although this method is a good approach in some situations, it can be inappropriate or even
dangerous under different circumstances. More sophisticated approaches are usually required when
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33. investigating corporate problems. If a company is experiencing a serious threat to its survival, be it
declining market shares or disagreements with the labor union, resources are mobilized to deal with
the problem. The company might already be divided into "parts", such as the accounting department,
the sales department, and so on. Problems affecting the entire company are often blamed on a
department, as when a loss in market shares causes executives to target the sales department for
investigation or punishment. The reason for the problem might seem obvious. The company must be
losing market shares because the salespeople are not selling the product. What is often lost in the
picture is the fact that the sales department depends on many other departments to do its job.
Deficiencies may be in any or all of them. Perhaps the management information services department
has not provided the salespeople with the computer support they need. Or maybe manufacturing has
been suffering from poor scheduling of orders and a backlog has developed. This will in turn make it
harder for the salespeople to sell the product to customers who want an immediate delivery. A number
of factors may be the cause of the problem, which may come to light only when the interactions
among all parts of the corporation, and not just the parts themselves, are examined.
Connecting the Pieces
We are viewing a system when we look at a group of individual parts, as well as the connections or
interactions among these parts. A corporation is an example of such a system, composed of many
departments that in turn act as systems themselves. When we study the parts and the interactions
between them, we in fact study the entire system.
The study of systems is not new. It dates back to the 1920s when researchers from different
disciplines began to see that many patterns were common to all fields. A new field, general systems
theory, developed around the notion that no matter how different the parts of individual systems were,
they were put together using a set of rules common to all. Systems theory suggests that knowledge of
one type of system can be applied to many other types. By studying interactions and connections
between the pieces of a system, we can gain knowledge that can be useful when confronted with other
problems.
Systems theory expands further to include two major fields in management science: systems thinking
and system dynamics.
Systems Thinking and System Dynamics
The ideas we have presented thus far are important in both systems thinking and system dynamics.
Systems thinking involves changing paradigms about the way the world works, the way corporations
function, and the human role in each. In systems thinking we look for interrelationships among
system elements. We do this to avoid placing blame in favor of finding the true, long-term solution to
a problem. Seeing the interrelationships can also help us find leverage points within a system (places
where a slight change will have a tremendous effect on the system's behavior). Gaining awareness
about how the system is built up and how it works can also help us avoid solutions that only treat the
symptoms of an underlying problem without curing the problem itself.
Systems thinking is powerful because it helps us see our own mental models and how these models
color our perception of the world. In many cases, it is difficult for us to alter our mental models. There
are always some beliefs or viewpoints that we are not willing to change, no matter what evidence is
presented against it. This causes a certain resistance to new concepts. Problems can occur, however,
when a rigid mental model stands in the way of a solution that might solve a problem. In such
situations, adherence to mental models can be dangerous to the health of the organization.
We all use mental models every day. Our minds do not contain real economic or social systems.
Instead, they contain representations - models - of reality. We use these models in all aspects of
decision-making. Being explicitly aware of our mental models can help us understand why we make
the decisions we do and how we can improve our decision-making processes. If everyone's mental
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