isee systems's Profile
Number of items: 98
Date joined: Jun 01 2016
isee systems's Work
#1
Goal Seeking
sim
⋮ 285 runs
#2
#3
External Resource
sim
⋮ 109 runs
#4
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.
sim
⋮ 2052 runs,
574 downloads
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supply chain
semiconductor
oscillation. production planning
capacity management
#5
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.
#6
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!
#7
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.
#8
Enron
sim
⋮ 306 runs
Business
#9
Draining
sim
⋮ 148 runs
#10
Compounding
sim
⋮ 135 runs
#11
COVID-19: Vertical Isolation in Brazil
Does the policy of vertical isolation allow a country to reopen its businesses and schools without i
... Read more
Does the policy of vertical isolation allow a country to reopen its businesses and schools without increasing COVID-19 cases or deaths? This simulator explores the outcomes of horizontal isolation (what we're doing now) and vertical isolation (only isolate the sick and the elderly).
sim
⋮ 4559 runs
Biology
Science
Education
COVID-19
coronavirus
#12
Dual Flow
sim
⋮ 135 runs
#13
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!
sim
⋮ 25710 runs,
912 downloads
Download Model
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Systems Thinking
zombies
epidemic
disease
susceptible
#14
Temperatures
Simulation showing min, max and average temperatures in the United States by month.
#15
Plant Succession
This simulation illustrates how plants in the ecosystems move throught the successional stages of fo
... Read more
This simulation illustrates how plants in the ecosystems move throught the successional stages of forb, grass, shrub, pine and hardwood. Plants in each stage build soil quality, thereby creating conditions for the development of the subsequent stage. As a stage establishes a sufficient presence in the ecosystem, it crowds out the previous stage.
sim
⋮ 148 runs
Environment
Biology
Science
Ecology
#16
Interfaces in Stella Architect
Example interface features in Stella Architect in a mouse population simulation
sim
⋮ 1256 runs
Biology
Ecology
Interface; Capacity Contraint; Population
#17
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.
#18
Microchips and the Auto Industry
After 2 years unreliable supply chain of microchips, the auto industry is struggling to adopt.
#19
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!
#20
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.
#21
Airport Runway Capacity
Examine the implications of an increasing number of landing airplanes on a fixed capacity runway.
sim
⋮ 1758 runs,
411 downloads
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Reengineering
discrete modeling
queues
iThink
process improvement
#22
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.
#23
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.
sim
⋮ 5195 runs,
593 downloads
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Temperature
proportional integral controller
Newton's law
heat pump
#24
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
sim
⋮ 2058 runs,
272 downloads
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Disaster relieft
Water
Mark Heffernan
George McDonnel
scenarios
#25
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.
#26
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.
#27
Success to the Successful
In the "Success to the Successful" archetype
the behavior pattern created is a widening gap betwee
... Read more
In the "Success to the Successful" archetype
the behavior pattern created is a widening gap between the successful and the unsuccessful. Understanding the structure of the system helps us to see that the reasons for this gap aren't necessarily about competence.
In other words, winners aren't always the best - it is often the structure that determines who wins. By understanding how the system works, we can avoid falling into the trap of a win-lose situation and work to create a win-win environment.
sim
⋮ 129 runs
Archetype
#28
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.
#29
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.
#30
#31
Optimization Example
Demonstrates the use of optimization on the interface.
sim
Optimization
#32
Predator Prey Dynamics
This simple model illustrates the basic relationships that govern the dynamics of a predator-prey sy
... Read more
This simple model illustrates the basic relationships that govern the dynamics of a predator-prey system.
sim
⋮ 1776 runs
Environment
Biology
Science
Ecology
#33
COVID-19: Vaccinations in the USA
This model explores the vaccination program in the United States and its effort to control the COVID
... Read more
This model explores the vaccination program in the United States and its effort to control the COVID-19 pandemic. It includes vaccine hesitancy, people's behavior in response to perceived risk, and vaccine effectiveness.
sim
⋮ 3791 runs
Biology
Science
Education
COVID-19
Coronavirus
#34
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?
#35
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.
#36
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
sim
⋮ 2055 runs,
173 downloads
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Thermodynamcis
adaptation
poiklothermic
homeothermic
Warm-blooded
#37
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.
sim
⋮ 409 runs
School Reform
#38
Baby Formula Shortage in USA
In February 2022 an Abbott production plant shut down causeing a months long sever baby formula shor
... Read more
In February 2022 an Abbott production plant shut down causeing a months long sever baby formula shortage in the USA. This model looks at the dynamics of that shortage and how parental anxiety played a part.
#39
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.
#40
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.
#41
Interface Workshop Sim
sim
⋮ 145 runs
#42
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.
sim
⋮ 7 runs
Extrovert
introvert
#43
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.
#44
Climate Champions: Beavers
This short story illustrates the value of beaver-created environments for drought and wildfire resis
... Read more
This short story illustrates the value of beaver-created environments for drought and wildfire resistance.
#45
Supply Chain Management without Forecasting
Accurate demand forecasting is an essential part of most supply chain management algorithms. Yet, s
... Read more
Accurate demand forecasting is an essential part of most supply chain management algorithms. Yet, supply even in the most diligently managed chains can deviate widely from demand. Additionally, any disturbance in demand will often be amplified in a supply chain creating what is known as bullwhip effect. This simulation uses three parsimonious models to demonstrate that supply can be regulated reliably without forecasting demand. The inspiration for these models comes from PID (Proportional, Integral, Derivative) control in engineering controllers that utilize multiple functions of error (discrepancy between goal and actual condition) to regulate a quantity.
#46
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.)
#47
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.
sim
⋮ 597 runs,
336 downloads
Download Model
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Customer satisfaction
employee satisfaction
human resourses
#48
Pharmacokinetics
In this simple example try to keep a drug in a patients bloodstream at the thereputic level over a 4
... Read more
In this simple example try to keep a drug in a patients bloodstream at the thereputic level over a 48 hour period without the drug levels going too low or two high.
sim
⋮ 88 runs
Biology
Science
Pharmacokinetics
drug levels
#49
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.
sim
⋮ 336 runs,
88 downloads
Download Model
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Calculus
relates rates
Pythagorean Theorem
Balloon
distance
#50
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?
#51
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.
#52
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.
#53
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.
#54
Story of the Month Reissue: Deficit
Examines the often-confused concepts of deficits versus surpluses and tax cuts versus tax rebates.
#55
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.
sim
⋮ 8226 runs
Guns
Schools
Public Policy
Violence
Bullying
#56
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.
#57
An Abundance of Hops
Is the hops imbalance in the craft beer maket a cause for concern for the industry?
#58
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.
#59
COVID-19 Simulator
This simulator looks at the spread of COVID-19 (Coronavirus) through a city. You can implement poli
... Read more
This simulator looks at the spread of COVID-19 (Coronavirus) through a city. You can implement policies, change assumptions about the disease and see the impacts in realtime.
sim
⋮ 123017 runs
Biology
Science
Education
COVID-19
Coronavirus
#60
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.
#61
Pendulum Story
In this model, you will explore the effect that string length, bob mass, and initial starting positi
... Read more
In this model, you will explore the effect that string length, bob mass, and initial starting position have on the motion of the pendulum, ignoring the effects of friction and air resistance. Then, you will investigate how the motion is changed when other forces are taken into account.
sim
⋮ 137 runs
Science
Math
physics
gravity
friction
#62
COVID-19 Economy Model
Our latest Story of the Month explores the economic cost of the COVID-19 stay-at-home orders in the
... Read more
Our latest Story of the Month explores the economic cost of the COVID-19 stay-at-home orders in the United States. Are there policies that can help mitigate these costs? Do the provisions of the CARES Act have a significant effect on the economic outcomes? Find out in our new simulation.
sim
⋮ 2378 runs
Business
Economics
Education
COVID-19
coronavirus
#63
The Overturned Truck on the Highway
You are driving on the highway and around the curve is an overturned truck 100 meters away
(about
... Read more
You are driving on the highway and around the curve is an overturned truck 100 meters away
(about 1 football field). Can you stop in time?
sim
⋮ 119 runs
physics
reaction time
#64
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.
sim
⋮ 2872 runs,
296 downloads
Download Model
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Trump
missing middle
vicious cycle
storytelling
manufacturing jobs
#65
Modeling COVID-19 Effectively
This simulation demonstrates the importance of modeling the COVID-19 epidemic properly using high or
... Read more
This simulation demonstrates the importance of modeling the COVID-19 epidemic properly using high order delays vs. perfect mixing.
sim
⋮ 454 runs
Environment
Biology
Science
Education
COVID-19
#66
Effects of Assistance on Life Trajectories
Looks at the effect of food, housing and skills interventions on individual life trajectories.
sim
⋮ 257 runs
#67
Tobacco Use Prevention Lab
This model focuses on the populations of smokers and nonsmokers as they age. In addition, it looks a
... Read more
This model focuses on the populations of smokers and nonsmokers as they age. In addition, it looks at the processes of picking up and quitting the habit. Finally, the model looks at health care costs and deaths associated with smoking.
sim
⋮ 153 runs
Science
Education
iThink
Smoking
Quit smoking
#68
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?
#69
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!
sim
⋮ 7847 runs,
540 downloads
Download Model
Download Model
Automation
job loss
AI
artificial intelligence
labor force
#70
SOTM Reissue: The Israeli-Palestinian Conflict
Originally published in 2003 this model looks at the escalating violence in the Israeli/Palestinian
... Read more
Originally published in 2003 this model looks at the escalating violence in the Israeli/Palestinian conflict and how Systems Thinking might prove useful in building greater insight into both the causes of the conflict and what would need to happen to achieve a lasting peace.
sim
⋮ 1 run
Conflict
peace
escalation
SOTM
#71
Reversible Reactions
In this simple Stella-based Laboratory, you’ll have the opportunity to deepen your understanding of
... Read more
In this simple Stella-based Laboratory, you’ll have the opportunity to deepen your understanding of Le Chatelier’s principle. The lab begins with a simple, idealized model of a reversible reaction. You will be able to see clearly the effect that reversibility plays in an overall dynamic of the reaction. Then, in the final part of the lab, you will be able to experiment with a classic reaction.
sim
⋮ 147 runs
Science
Education
Chemistry
#72
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.
#73
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.
sim
⋮ 1626 runs,
492 downloads
Download Model
Download Model
Energy
residential
industrial
agricultural
energy usage
#74
Non-Separable 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.
#75
#76
traffic congestion
Explores the dynamics of road use and road construction.
#77
#78
#79
Systems In Focus: Conservation
Fishing areas are within the commons, which encourages greater investment in ships when there is dem
... Read more
Fishing areas are within the commons, which encourages greater investment in ships when there is demand. More importantly, we can never really know the population of the given fishery and therefore whether it is in danger of being fished out. This model explores the trade-offs between investing in more ships to catch more fish and the long-term viability of the fishery.
#80
External Resources Structure
External Resources Generic Structure
#81
Systems In Focus: Manufacturing
In this simple example, we have modeled the basics of a bottling plant. Before we can model the proc
... Read more
In this simple example, we have modeled the basics of a bottling plant. Before we can model the process however, we need to consider the supplies required to create the final product, in this case, water. A bottling plant requires a constant supply of purified water. It is usually run through three sets of filters that remove smaller and smaller particles before being sterilized.
#82
COVID-19 Model By Age
This models the COVID-19 pandemic as an SEIR model disaggregated by age. DIfferent ages have differ
... Read more
This models the COVID-19 pandemic as an SEIR model disaggregated by age. DIfferent ages have different contact rates, death rates, and conformance to social distancing. A thrid-order material delay is used to create the distribution for the tie to become infected and the time to recover.
#83
COVID-19 Economy
This models the economic impacts of an extended shutdown due to the coronavirus pandemic and explore
... Read more
This models the economic impacts of an extended shutdown due to the coronavirus pandemic and explore the policies adopted by the United States to mitigate these effects.
#84
Stock-adjustment
Example of stock-adjustment model for TA Time
#85
#86
#87
Draining structure
Draining generic structire
#88
#89
COVID-19 Model
This simulator walks the user through a model showing the spread of the COVID, or Corona Virus throu
... Read more
This simulator walks the user through a model showing the spread of the COVID, or Corona Virus through a city. You can implement policies, change assumptions about the disease and see the impacts in realtime.
#90
#91
Compounding Structure
Compounding generic structure
#92
Systems in Focus: Agriculture
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.
#93
Systems In Focus: Business
Deciding when to expand a business is difficult in any industry. For the airline industry, there are
... Read more
Deciding when to expand a business is difficult in any industry. For the airline industry, there are both large investments and long delays involved in expansion, making it important to test your assumptions as you go.
#94
Systems In Focus: Energy
Building capacity in alternative energy sectors takes time and large investments. The transition to
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Building capacity in alternative energy sectors takes time and large investments. The transition to other sources has to be financially feasible, as well as timely to prevent further damage from pollution. How can the mix of electricity generation technology change, based on both cost and pollution? This Systems in Focus model analyses how capacity can be developed in different energy sectors over time.
#95
Systems In Focus: Water
A lot is happening behind the scenes to create this picturesque vista. Rainfall on land creates runo
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A lot is happening behind the scenes to create this picturesque vista. Rainfall on land creates runoff and therefore stream flow. Some of this runoff is absorbed into the soil. Some of that flows beneath the ground to the stream and some returns to the air through evapotranspiration. Another part of it percolates further down through the soil layers to become part of the groundwater, which provides a base level flow for the stream. Using Stella Professional, we are able to draw a map that corresponds closely to the physical world and then simulate that map to see what happens. This both increases our understanding of how this system works and allows us to experiment with different policies that might lead to alternate, more desirable outcomes.
#96
Systems In Focus: Environment
One of the greatest environmental challenges we face is how to do more with less: Less raw materials
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One of the greatest environmental challenges we face is how to do more with less: Less raw materials, less pollution, less damage to the environment. This model shows the life-cycle assessment for the aggregate products manufactured and consumed in a firm, an industry, a region, a nation, or the world. It focuses on solid waste, though it would be easy to add air or water pollution generated and energy consumed at each stage.
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Environment
Ecology
Systems in Focus
Renewable Resources
Raw Material
Uploading a Bundle from Zip
Instead of creating bundles, categories, and assemblies one by one, you can upload a single zip file that contains all of your bundle's content. To create your zipped bundle, make a folder with your bundle's name and add subfolders with your categories' names. The folder tree should have the same structure that you want the categories to have in your bundle. Place your assembly .stmx files in the appropriate category folders, then zip your bundle folder and upload it using the Upload Bundle from Zip link above.
Assemblies, Bundles, and Categories
Assemblies are self contained models that demonstrate common ways to connect together building blocks and that can be used as parts of other models. This is analogous to using prefabricated wall and roof pieces to construct a house.
Bundles are groups of assemblies with a common use or theme. For example, a Health Care bundle might contain a variety of assemblies that aid in creating health care models. When you download assemblies from the isee Exchange™, you download an entire bundle, rather than individual assemblies.
Categories are subgroups of assemblies within a bundle. For example, a Health Care bundle might contain a Funding category for assemblies related to the management of hospital funds. All assemblies must be assigned to a category—they cannot be assigned to the root of a bundle.
Assemblies, bundles, and categories can be created and uploaded to the isee Exchange™ via the options on the Manage My Assemblies page. To learn more, visit our help pages, or take our assemblies tutorial.
Sim App (Sim)
An interface that allows users to interact with a model.
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.
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 isee 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.
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™.