The numerous Systems Archetypes popularized by Peter Senge, and others seem to be the source of great confusion for many. In response to this Eric Wolstenholme has endeavored to simplify the System Archetypes by mapping them to four generic archetypes.

Inventory Model v2.0 adds production and order lead time. As well as the ability to keep track if parts are on order for a production run. See also: Inventory Model v3.0.

There is much we can learn from the development of qualitative relationships models though once we begin to ask questions like how long, how much, when, etc., a qualitative most is not likely to be of much use. The following video demonstrates how, in a very simple goal-seeking structure with delay, depending on the delay, it can be almost impossible to intuit the implications of the interactions with any level of accuracy. The difficulty arises essentially from operating with outdated data. See also Archetypes.

Model is created by Gene Bellinger. Original model can be accessed from https://insightmaker.com/insight/2249/Adjusting-the-Shower-SFD.

Simplest Innovation diffusion model from Sterman's Business Dynamics Ch 9

The Self-Referening Model is one of the four basic model forms presented by Hannon & Ruth in Dynamic Modeling.

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This model is an attempt to understand the interactions within an economy in an attempt to determine where the leverage points are to stimulate an economy.

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Faced with a performance gap the two most obvious responses are to work harder or work smarter. There are trade offs associated with each, some obvious, some not so obvious.

Derived from Nobody Ever Gets Credit for Fixing Problems that Never Happened: Creating and Sustaining Process Improvement by Repenning and Sterman.

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Example of using Pulse function to create a recurring delay.

Causal Loop Diagram is an element of the Simulation with Insight Maker program.

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Bathtub model with filling control added. Running the model is essentially considered to be turning on the faucet and water will run into the bathtub until it is full.

OK, we have a problem. Yet, do we really know what the problem is? More often than not we look at the symptoms, consider them the problem and attempt to fix them. This actually dooms us to failure because they're only symptoms.

Inventory Model v4.0 calculates min days inv & max days inv and makes adjustments for desired service level. See also: Inventory Model v3.0.

21st Century Systems Thinking Skills as depicted b Viktor Vojko. Adapted from Systems thinking: critical thinking skills for the 1990s and beyond by Barry Richmond.

Rich Pictures, Causal Loop Diagrams and Stock & Flow Simulation Models are the three types of models most commonly used.

The simple savings account is used to demonstrate the nature of a reinforcing loop. Change the initial amount and interest rate and run the model to see the implications of changing these values.

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Macros are very useful for defining functions that need to be repeatedly at various places in the model.

There are limits to what one can infer from a qualitative model. It is typically beyond the capacity of humans to infer the behavior of complex situations with 2 or more feedback loops.

There are about fifteen known archetypes with an interesting set of relationships among them.

SystemsWiki's Musings

Purpose: Employ the Mono Lake model adapted from "Modeling the Environment" by Andrew Ford as a basis for developing a set of guidelines to support asynchronous multi-user model development.

Mono Lake is an ancient inland sea on the eastern side of the Sierra Nevada. From a policy point of view Mono Lake is the story of how a handful of people began a campaign to save a dying lake.

• 10.06.04 v1.0 created and documented by Bellinger. Initial problem with the reference mode has been fixed.

Part 1 demonstrates Picture primitives and Links to create representations of interactions. These are made visually attractive because the Picture primitives are overlay'd with images.

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In addition to identifying the relevant stakeholders it is essential to understand which elements of the situation are relevant to which stakeholders. Often this is quite apparent and at times it's not so obvious. 

What do activities of these images have in common?