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Number of items: 63
Date joined: Jun 01 2016

isee systems's Work

#1

Vacation

Do you ever feel like work is taking over your life? Burnout is generally characterized as a state o ... Read more
Do you ever feel like work is taking over your life? Burnout is generally characterized as a state of mental and physical exhaustion resulting in low productivity and de-personalization and is most likely caused by prolonged stress that does not dissipate. There are many different aspects that affect both the building and dissipation of burnout. This model focuses on workloads and vacations to see how they contribute to both your level of burnout and productivity. Use this model to ask questions about your workload and any benefits you would receive from taking a vacation. What happens when you suddenly have a bigger workload? What happens when work piles up? Does vacation increase or decrease your stress levels?
sim9341 runs, 196 downloads
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Vacation burnout stress productivity workload
#2

College Loans

Each year, the cost of a college education continues to rise and more and more students must turn to ... Read more
Each year, the cost of a college education continues to rise and more and more students must turn to student loans to complete their education. But as graduates leave college to embark on their careers, they face an almost Sisyphean struggle with student debt, forever facing an uphill battle while carrying a heavy burden, only to find they are getting nowhere! Whether you are graduating from college or just entering, we hope this model will enable you to better understand student loans and help plan for your future.
sim18241 runs, 501 downloads
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Student loans loans college interest repayment
#3

Headcount Strategy

Explore a consulting firm’s headcount strategy. Understand the relationship between growth rates, pr ... Read more
Explore a consulting firm’s headcount strategy. Understand the relationship between growth rates, promotion times, headcount pyramid ratios, and attrition rates. This model is based on actual work that was done with a very well-known consulting company (here, code-named TWBC, Inc.). The firm's strategic goals were well-articulated, and each made sense when written down in a list on a piece of paper. However, when subjected to the more rigorous, dynamic scrutiny that an iThink modeling effort provides, the goals (as is too often the case) turned out to be in conflict with one another--stimulating actions that worked at cross-purposes. Efforts to achieve one goal drove the firm farther away from achieving the others. The subsequent analysis conducted with the model also pointed the way toward resolving the internal strategic inconsistencies and putting the firm back onto a strategically sound growth path.
sim1349 runs, 210 downloads
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Headcount employees growth manager consultant
#4

Zombie Apocalypse

This is our first model in the From Imagination to Simulation series. It is a nod to the Halloween s ... Read more
This is our first model in the From Imagination to Simulation series. It is a nod to the Halloween season and investigates a zombie apocalypse! Our fascination with zombies continually grows with the help of movies, TV shows, and books that give a wide range of zombie possibilities. But what are the dynamics behind a zombie epidemic? This model will specifically look at the spread of a zombie outbreak and examine some of the variables that help and hinder the rate of infection. We hope you will continue to see the benefits and versatility of Systems Thinking and enjoy our new series, From Imagination to Simulation! Continue to ponder those out-of-the-ordinary problems. They may seem unrealistic, but perhaps some of their dynamics may resonate with reality. Check out our zombie apocalypse model to see if there is any chance for human survival!
sim10475 runs, 239 downloads
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Systems Thinking zombies epidemic disease susceptible
#5

School Reform

This Story of the Month reissue examines the complexities of school reform. Inspired by a major sch ... Read more
This Story of the Month reissue examines the complexities of school reform. Inspired by a major school reform effort in Philadelphia, this story explores some of the potential unintended consequences. What happens when the focus of "fixing schools" becomes increasing scores on standardized tests? The Story of the Month series was originally issued starting in May of 2001. While many things have changed since then, many of the issues remain relevant. From corporate corruption, to terrorism, to greenhouse gasses, each story analyzed a past headline news topic from a systems thinking perspective. These topics were modeled using STELLA or iThink with the hopes to gain perspective on the system, stimulate discussion and perhaps adjust our assumptions. isee systems has been re-releasing each Story of the Month from our archives, as originally developed, with an easy-to-access isee Sim Exchange.
sim332 runs
School Reform
#6

Humanitarian Aid

A look at disaster relief under uncertain local government scenarios. It looks at how long it might ... Read more
A look at disaster relief under uncertain local government scenarios. It looks at how long it might take to establish clean water thru flying in bottled water and constructing wells. There is also the impact on spread of disease and survival due to lack of water. Created by Mark Heffernan and George McDonnel
sim1374 runs, 140 downloads
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Disaster relieft Water Mark Heffernan George McDonnel scenarios
#7

Amalgamated Industries

sim2018 runs, 153 downloads
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#8

The Wolves of Yellowstone

Keystone species are defined as a plant or animal that plays a unique role in the way the ecosystem ... Read more
Keystone species are defined as a plant or animal that plays a unique role in the way the ecosystem functions. But what would happen if that species were removed? What ripple effects would be caused by the absence of this species? We can examine these questions by looking at the wolf population in Yellowstone National Park. Wolves once flourished in Yellowstone and its surrounding areas. However, soon after the area was settled, misperceptions caused by fear and hatred fueled a large extermination effort of the wolves. For nearly 70 years, wolves were absent from Yellowstone. During this time, the ecosystem changed and diminished until scientists realized the value of the wolves and reintroduced them to Yellowstone. This model, built in iThink, uses storytelling to understand the dynamics of this keystone species. What animals were affected by their presence or absence. See how wolves play a part in not only population control of their prey but other animals and even plants far down the trophic levels.
sim20 runs, 217 downloads
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Keystone species Wolves wolf Trees Aspen
#9

Guns At School

This interface explores the public policy issue of gun violence at schools. As a policymaker, you c ... Read more
This interface explores the public policy issue of gun violence at schools. As a policymaker, you can explore different initiatives to see which are most effective at reducing this violence.
sim5213 runs
Guns Schools Public Policy Violence Bullying
#10

The Power of The Missing Middle

Systems Thinking at Large takes a closer look at the suprising win for Trump. Focusing on the missi ... Read more
Systems Thinking at Large takes a closer look at the suprising win for Trump. Focusing on the missing middle population and their possible power in the voting booth.
sim2090 runs, 116 downloads
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Trump missing middle vicious cycle storytelling manufacturing jobs
#11

Airport Runway Capacity

Examine the implications of an increasing number of landing airplanes on a fixed capacity runway.
sim594 runs, 165 downloads
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Reengineering discrete modeling queues iThink process improvement
#12

Bricks to Clicks

Experience the dynamics of making a business shift from traditional to e-commerce. Simulate differen ... Read more
Experience the dynamics of making a business shift from traditional to e-commerce. Simulate different scenarios for how you’ll allocate spending on marketing versus infrastructure. You will see one of the more common dynamics in making a business shift, what Systems Thinkers refer to as the "worse before better" dynamic. If initial investments are made in the infrastructure quality rather than in marketing, total customers will actually fall for awhile. But if increasing amounts are spent on marketing (once the infrastructure is in place) then total customers will begin to explode. And the transition becomes successful!
sim285 runs, 87 downloads
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retail strategy iThink
#13

Multiple Retailer Supply Chain

Experience the dynamics of overshooting/undershooting inventory typical in the retail industry. Tour ... Read more
Experience the dynamics of overshooting/undershooting inventory typical in the retail industry. Tour this supply chain model to understand the structure from the factory through multiple retailers to the consumer.
sim147 runs, 156 downloads
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iThink inventory arrays conveyors supply chain
#14

Customer-Employee Satisfaction

Research shows a strong correlation between employee satisfaction and customer satisfaction. Underst ... Read more
Research shows a strong correlation between employee satisfaction and customer satisfaction. Understand the correlation through this model, which illustrates the causal relationship between the two.
sim230 runs, 137 downloads
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Customer satisfaction employee satisfaction human resourses
#15

Energy Demand Lab

This simple model explores the demand dynamics for a state's energy usage. For three sectors (reside ... Read more
This simple model explores the demand dynamics for a state's energy usage. For three sectors (residential, industrial, and agricultural) you can adjust the size of initial user base, the growth rate for the number of users, and the rate for the change in demand per user.
sim412 runs, 214 downloads
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Energy residential industrial agricultural energy usage
#16

Energy (2002)

Can Energy Prices Really Be Passed on to the Consumer? Energy literally fuels every aspect of today' ... Read more
Can Energy Prices Really Be Passed on to the Consumer? Energy literally fuels every aspect of today's economy. When energy costs increase, many businesses will increase prices thereby "passing on" the cost to consumers. This story helps to explain some of the broader reaching impacts of such a policy. This model was created by Steve Peterson.
sim17 runs, 145 downloads
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Energy consumer energy prices power policy
#17

Housing Supply and Demand

Use this learning lab to investigate the housing crisis. Play with interest rates as if you are Chai ... Read more
Use this learning lab to investigate the housing crisis. Play with interest rates as if you are Chairman of the Federal Reserve and see the impact on housing supply and demand. What happens when banks relax mortgage requirements and more people qualify to buy homes?
sim1872 runs, 257 downloads
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Modules finance debt economics housing demand
#18

Compounding

sim55 runs
#19

Draining

sim78 runs
#20

Dual Flow

sim73 runs
#21

External Resource

sim60 runs
#22

Goal Seeking

sim131 runs
#23

Automation

Innovation often raises concerns about job losses, increasingly so in the past century with widespre ... Read more
Innovation often raises concerns about job losses, increasingly so in the past century with widespread automation and advanced artificial intelligence. Should we start to fear for our job security or will the creative potential in society maintain the labor force? Explore this model to see some of the interesting possibilities!
sim1881 runs, 161 downloads
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Automation job loss AI artificial intelligence labor force
#24

Business Cycle Dynamics

Business cycles are a fact of life for many industries. Market demand peaks one year only to plummet ... Read more
Business cycles are a fact of life for many industries. Market demand peaks one year only to plummet a year or two later. In this case study of a semiconductor business, Henk Akkermans, Professor of Supply Network Dynamics at Tilburg University, explores different policy options for order handling, production planning and capacity management to reduce oscillation and improve system performance.
sim685 runs, 190 downloads
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supply chain semiconductor oscillation. production planning capacity management
#25

Resource Allocation

One of the most challenging tasks in most organizations is the allocation of headcount between time- ... Read more
One of the most challenging tasks in most organizations is the allocation of headcount between time-competing activities. In this model, you will have a chance to explore these sorts of dynamics in the context of a consulting firm, where the same headcount can be allocated to business development activities and client service delivery. You'll see the classic pattern of "Feast or Famine," or the so-called "pig in a snake," emerge.
sim150 runs, 127 downloads
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human resources headcount
#26

Service Call Center Dynamics

One organization in the service delivery business experienced a situation where the number of delive ... Read more
One organization in the service delivery business experienced a situation where the number of delivery requests increased dramatically due to a seasonal promotion. This increase in requests caused an overload on the service delivery staff by not only having more people requesting service, but also because the amount of time spent with each customer increased. This model is designed to describe why this occurred in a way that can be transferable to other service delivery organizations.
sim231 runs, 106 downloads
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discrete modeling queues conveyors cycle time
#27

Simple Balanced Scorecard

This simple model incorporates the four perspectives of the Balanced Scorecard management strategy i ... Read more
This simple model incorporates the four perspectives of the Balanced Scorecard management strategy into a dynamic whole.
sim279 runs, 76 downloads
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Balance Scorecard
#28

Ski Resort Dynamics

This practice field provides a risk-free environment for exploring different capacity expansion stra ... Read more
This practice field provides a risk-free environment for exploring different capacity expansion strategies for a ski resort. Apply the insights to a wide range of process improvement efforts.
sim257 runs, 59 downloads
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Conveyors reenginering cycle time. crowding
#29

President & Prime Minister

Whose coffee cools faster? This question quickly becomes relevant for the president and the prime mi ... Read more
Whose coffee cools faster? This question quickly becomes relevant for the president and the prime minister as they travel together in a plane. Understand the cooling process. Then experiment with a cooling model.
sim123 runs, 38 downloads
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President Prime Minister Coffee Newton Temperature
#30

Story of the Month Reissue: Deficit

Examines the often-confused concepts of deficits versus surpluses and tax cuts versus tax rebates.
sim784 runs, 32 downloads
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tax cuts tax rebates deficit surplus social security
#31

Temperatures

Simulation showing min, max and average temperatures in the United States by month.
sim454 runs, 51 downloads
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Yearly temperature; svg animation
#32

ER Simulation

ER Simulation
sim594 runs, 69 downloads
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SVG Animation; Discrete
#33

Virtual Hamlet

Use this virtual laboratory to explore the plot and character development in one of Shakespeare's wi ... Read more
Use this virtual laboratory to explore the plot and character development in one of Shakespeare's widely read plays . What would happen if Hamlet where a “man of actions” as opposed to a “man of thought?” How would different characterizations change both the timing and the overall ending of the play?
sim60 runs, 15 downloads
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Hamlet Literature soft variables intangibles Stella
#34

One-dimensional diffusion

Simulates the diffusion of heat through a one meter metal bar when the ends are held at a constant 1 ... Read more
Simulates the diffusion of heat through a one meter metal bar when the ends are held at a constant 100 degrees.
sim63 runs, 15 downloads
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diffusion temperature spactial modeling arrays
#35

Animal Temperature

Explore the laws of thermodynamics with this animal temperature model. As you experiment, think abo ... Read more
Explore the laws of thermodynamics with this animal temperature model. As you experiment, think about animal adaptations and consider the following: What problems do small animals face compared to large animals in hot and cold environments? What problems do cold-blooded (poiklothermic) animals face compared to warm-blooded (homeothermic) animals? What is it that insulation really does for animals? The story behind this model is explained in a chapter of Tracing Connections
sim184 runs, 38 downloads
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Thermodynamcis adaptation poiklothermic homeothermic Warm-blooded
#36

Mystery on the Island of Borneo

What do the bubonic plague, falling roof beams and dead fish have in common? Read this story and unf ... Read more
What do the bubonic plague, falling roof beams and dead fish have in common? Read this story and unfurl the STELLA model to solve the mystery.
sim3 runs, 22 downloads
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Borneo mystery cats DDT Geckos
#37

Virtual Bungee

Virtual bungee jumpers can experiment with different body weights and bungee cord strengths. Then th ... Read more
Virtual bungee jumpers can experiment with different body weights and bungee cord strengths. Then they experiment with different platform heights and even different gravitational fields.
sim99 runs, 11 downloads
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Virtual oscillation Stella Gravity Physics
#38

Cash for Clunkers

On July 24th, 2009 the Car Allowance Rebate System (CARS), commonly known as "Cash for Clunkers," be ... Read more
On July 24th, 2009 the Car Allowance Rebate System (CARS), commonly known as "Cash for Clunkers," began processing rebate claims. The $1 billion appropriated for the system was exhausted just SIX days later. This simulation explores an alternative program that is self-sustaining AND reduces automobile emissions. Using a combination of fees and rebates this program can finance itself (no emergency appropriations from Congress), reduce gasoline consumption (putting cash back in consumer's pockets), AND contribute to cleaner air for us all!
sim24 runs, 22 downloads
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Cash Cars freebates policy iThink
#39

Community Model Building: Drought

In a pioneering attempt, isee systems hosted a Community Model Building webinar on Drought in Califo ... Read more
In a pioneering attempt, isee systems hosted a Community Model Building webinar on Drought in California, a severe and complex issue facing humanity. We discussed live with the community what the main problem variables are and how they change over time. We then built a qualitative model (causal loop diagram) based on participants' input. This quantitative model (stock and flow diagram) model was built in the background, representing the discussion.
sim122 runs, 45 downloads
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Community water drought climate science
#40

The Balloon Problem

This model illustrates how a simple interface can facilitate experimentation with a mathematics mode ... Read more
This model illustrates how a simple interface can facilitate experimentation with a mathematics model. The model depicts a classic problem in calculus known as the balloon problem. Experiment with different distances and velocities.
sim86 runs, 16 downloads
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Calculus relates rates Pythagorean Theorem Balloon distance
#41

Temperature Control

Conduct experiments and try to maintain a constant temperature in a house that uses a climate contro ... Read more
Conduct experiments and try to maintain a constant temperature in a house that uses a climate control system. Turn on and off the Proportional and Integral controllers that drive the heat pump. Experiment with different outside temperatures, and different thermostat settings. See what happens when you change the house's insulation by adjusting the temperature loss constant.
sim123 runs, 24 downloads
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Temperature proportional integral controller Newton's law heat pump
#42

Sustainable Shrimping

This Learning Environment should help you understand some basic population dynamics and their releva ... Read more
This Learning Environment should help you understand some basic population dynamics and their relevance to policy development for sustainable shrimping practices. While the specific context is shrimping, the concepts learned should be transferable to other harvesting situations (fishing, hunting, tree farming, etc.)
sim177 runs, 37 downloads
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population dynamics shrimp harvesting
#43

Supply Chain Dynamics

Use this model to explore the implications of supplier, producer, and consumer attributes on overall ... Read more
Use this model to explore the implications of supplier, producer, and consumer attributes on overall supply chain performance.
sim131 runs, 70 downloads
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Supply Chain inventory main chain reengineering
#44

Distance and Time

Experiment with different velocities and find out how they impact the solution to this typical dista ... Read more
Experiment with different velocities and find out how they impact the solution to this typical distance and time problem. See how STELLA helps students make sense of often difficult to understand mathematical concepts and equations.
sim58 runs, 21 downloads
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velocity distance time
#45

Extraverts and Introverts

This map (not a running simulation model) uses STELLA's storytelling feature to explore the concepts ... Read more
This map (not a running simulation model) uses STELLA's storytelling feature to explore the concepts of extraversion and introversion as popularized in the Myers-Briggs personality test.
sim3 runs
Extrovert introvert
#46

H1N1 Flu Outbreak

What is most effective in controlling the outbreak of a flu virus in schools? Is it better to vaccin ... Read more
What is most effective in controlling the outbreak of a flu virus in schools? Is it better to vaccinate or stay home? Use this Learning Lab to understand how infectious disease spreads and why the World Health Organization signaled the 2009 H1N1 (also called “swine flu”) outbreak as a pandemic.
sim274 runs, 47 downloads
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Flu outbreak SIR model infections desease pandemic
#47

Michaelis-Menten Dynamics

The Michaelis-Menten equations are taught in virtually any unit on enzyme kinetics. The problem, for ... Read more
The Michaelis-Menten equations are taught in virtually any unit on enzyme kinetics. The problem, for most students, is that the equations are abstract, and it's difficult for students to develop an intuitive sense for the processes the equations are being used to describe. This model provides a simple, physically-intuitive treatment of the enzyme kinetics phenomenon.
sim40 runs, 20 downloads
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biochemistry enzyme kinetics
#48

Non-Seperable Differential Equations

Analytically daunting or deceptively simple? The model represents a classic problem—that of mixing h ... Read more
Analytically daunting or deceptively simple? The model represents a classic problem—that of mixing hot and cold water in a bathtub. Experiment with different water temperatures and with different flow rates, showing the overall impact on the temperature of water in the tub.
sim80 runs, 23 downloads
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temperature water
#49

An Abundance of Hops

Is the hops imbalance in the craft beer maket a cause for concern for the industry?
sim346 runs, 23 downloads
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Supply chain hops beer surplus shortage
#50

Understanding the Measles Outbreak

The current 2019 measles outbreak is the highest since the early '90s and is drawing much attention ... Read more
The current 2019 measles outbreak is the highest since the early '90s and is drawing much attention from the media and the public. This model walks investigates how measles spreads in a population and what policies work best for reducing that spread.
sim2603 runs, 88 downloads
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Measles vaccine infectious disease quarantine WOM
#51

Natural Selection Pressure

In this model, a rabbit population comes under a natural selective pressure from a fox population. T ... Read more
In this model, a rabbit population comes under a natural selective pressure from a fox population. The average speed of the rabbit population increases as a result. You can experiment with the strength of the natural selective force.
sim36 runs, 23 downloads
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Biology predator-prey
#52

Compounding Structure

Compounding generic structure
model333 downloads
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compounding generic structure
#53

Draining structure

Draining generic structire
model346 downloads
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draining generic structure decay
#54

External Resources Structure

External Resources Generic Structure
model251 downloads
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Generic structure external resources
#55

Rank array

model267 downloads
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Rank array buitlin
#56

Population

model428 downloads
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#57

Resources and Population

model670 downloads
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#58

Identify structure

model395 downloads
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#59

resources allocation

model453 downloads
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#60

Stock-adjustment

Example of stock-adjustment model for TA Time
model385 downloads
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#61

Co-Flow

Example for TA time
model422 downloads
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#62

Dairy Cows

Agriculture offers many modeling opportunities. In this Systems in Focus, we look at the life cycle ... Read more
Agriculture offers many modeling opportunities. In this Systems in Focus, we look at the life cycle of a dairy herd, including milk production. This model could be used as the basis for methane production control, trade agreements about milk and how that impacts herd size, increasing production with demand, etc. Visit https://iseesystems.com/resources/systems-in-focus/agriculture/ for more information.
model1701 downloads
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Systems in Focus agriculture cows dairy
#63

traffic congestion

Explores the dynamics of road use and road construction.
model1271 downloads
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traffic urban planning congestion
X

Sim App (Sim)

An interface that allows users to interact with a model.

Image of a sim

Sim apps allow users to interact with a model using buttons, sliders, knobs, tables, graphs, and storytelling. These interactions help users understand how parts of a system interact.

Interfaces are created by model authors in the Stella desktop software and can be uploaded to the isee Exchange.

Model

A diagram that represents how elements in a system influence one another.

Image of a model

Models are mathematical representations of how elements in a system are connected and interact (e.g., ecosystems, organizations, supply chains). When running models on the Exchange, results can be viewed in output devices like graphs and tables.

Models appear in the isee Exchange directory when authors upload them from the Stella® desktop software or create them with Stella Online™.

Causal Loop Diagram (CLD)

A map that represents the feedback structure of a system.

Image of a CLD

CLDs are high-level maps that represents the feedback structure of a system and easily communicate the essence of a model. They appear in the isee Exchange when authors upload them from the Stella desktop software or create them with Stella Online™.