Simple Models

These models and simulations have been tagged “Simple”.

Exercise 1. 'Water
 in bathtub' is the stock, measured as a volume of water, in L. The bath is initially empty. The bath receives water from the taps ('Variable inflow from tap', in 
L/min) and loses water to the drain ('Constant outflow to drain', in 
L/min). 'Twiddling the taps' automatically swit
Exercise 1. 'Water in bathtub' is the stock, measured as a volume of water, in L. The bath is initially empty. The bath receives water from the taps ('Variable inflow from tap', in L/min) and loses water to the drain ('Constant outflow to drain', in L/min). 'Twiddling the taps' automatically switches the inflow from 40 L/min to 20 L/min at 5 minute (300 second) intervals. The outflow remains constant at 30 L/min.

4 4 months ago
This is an introductory conceptual model that introduces key concepts in the management of lakes subject to nutrient inputs from human activity.
This is an introductory conceptual model that introduces key concepts in the management of lakes subject to nutrient inputs from human activity.
 Exercise 2. 'Water
 in bathtub' is the stock, measured as a volume of water, in L. The bath initally holds 100 L of water. The bath receives water from the taps ('Variable inflow 
from tap', in 
L/min) and loses water to the drain ('Constant outflow to drain', in 
L/min). 'Twiddling the taps' gradu
Exercise 2. 'Water in bathtub' is the stock, measured as a volume of water, in L. The bath initally holds 100 L of water. The bath receives water from the taps ('Variable inflow from tap', in L/min) and loses water to the drain ('Constant outflow to drain', in L/min). 'Twiddling the taps' gradually ramps the inflow between a minumum of 0 L/min and a maximum of 60 L/min within each 5 minute (300 second) intervals. The outflow remains constant at 30 L/min.

4 months ago
A quick population rate model to help get acquainted to modular designs.
A quick population rate model to help get acquainted to modular designs.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
A quick population rate model to help get acquainted to modular designs.
A quick population rate model to help get acquainted to modular designs.
This is an introductory model that presents key concepts in the management of lakes subject to nutrient inputs from human activity.
This is an introductory model that presents key concepts in the management of lakes subject to nutrient inputs from human activity.
WIP from SDR  article  Understanding decision making about balancing two stocks: the faculty gender balancing task  See also  IM hint for optimal answer
WIP from SDR article Understanding decision making about balancing two stocks: the faculty gender balancing task  See also IM hint for optimal answer
Simple model for new product sales that contemplates the effect of success and competition.    Sales initially grow as the new product moves from introduction into growth.  Sales success attracts competitors who introduce their own products which reduces sales growth of the new product.     Eventual
Simple model for new product sales that contemplates the effect of success and competition.

Sales initially grow as the new product moves from introduction into growth.  Sales success attracts competitors who introduce their own products which reduces sales growth of the new product.

Eventually the total number of products that the market can bear are sold which stops further sales.

More advanced models could contemplate how competition affects price, how new successful products from competitors take market share, etc.
A quick population rate model to help get acquainted to modular designs.
A quick population rate model to help get acquainted to modular designs.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
WIP Model   IM insight  from SDR  article  Understanding decision making about balancing two stocks: the faculty gender balancing task  with added optimising structure hints
WIP Model  IM insight from SDR article Understanding decision making about balancing two stocks: the faculty gender balancing task  with added optimising structure hints
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
Exercise 2. The bath initially holds 100 L of water. Water flows in through the tap at a variable rate (L/min) and flows out through the drain at a constant rate (30 L/min). Control of the tap is pre-set.
Exercise 2. The bath initially holds 100 L of water. Water flows in through the tap at a variable rate (L/min) and flows out through the drain at a constant rate (30 L/min). Control of the tap is pre-set.

This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
This model fills a bathtub, while outflow occurs at a flow determined by the volume of water (or pressure at outlet) of the bathtub. It could just as well be a dam or lake that is modeled.
A toy model to see what happens to employment when people must move through various states to get to certain jobs
A toy model to see what happens to employment when people must move through various states to get to certain jobs