Workforce, Inventory and Oscillation model from Vensim user guide.

From Jay Forrester' Principles of Systems

Workforce and Inventory model

This model includes Average Sales in Orders to bring some stability and allows Inventory to attain the level of Desired Inventory.

It is a simple model to show how different parameters like inventory adjustment time and delay in ordering affect the inventory replenishment system. User can change values of all the parameters.

A demonstration of a simple min/max inventory system

This is a first go at a simple inventory system. No delays between Orders and Deliveries. Inventory fails to attain the level of Desired Inventory.

From Jay Forrester' Principles of Systems

Free to air TV channels mostly receive income from sales of advertising. Advertising inventory gains value from TV channel ratings, that are created by high quality content. High quality content is created with investments and content promotion increases content awareness, thus increases TV channel appeal.
Advertising and promotion inventories share same space that is left after program is set up.
More over marketing has targets to increase TV channel appeal.

This model includes Average Sales in Orders to bring some stability and allows Inventory to attain the level of Desired Inventory.

This model includes Average Sales in Orders to bring some stability and allows Inventory to attain the level of Desired Inventory.

My first attempt at a "rich pic" to describe an inventory process.

Models the behaviour of ​Blood Bank and Hospital blood inventories in response to a step change in the demand for transfusions.  Delays can be set for the delivery of blood to the hospitals and for the response of donors to a request for more blood.

This model assumes Sales are constant and used to calculate the number of items on orders

This model assume Sales increase 10% and used to test to response of the number of items on orders

Models the behaviour of ​Blood Bank and Hospital blood inventories in response to a step change in the demand for transfusions.  Delays can be set for the delivery of blood to the hospitals and for the response of donors to a request for more blood.

This model includes Average Sales in Orders to bring some stability and allows Inventory to attain the level of Desired Inventory.

This model using Random function

This model includes Average Sales in Orders to bring some stability and allows Inventory to attain the level of Desired Inventory.

This model includes Average Sales in Orders to bring some stability and allows Inventory to attain the level of Desired Inventory.

This is a first go at a simple inventory system. No delays between Orders and Deliveries. Inventory fails to attain the level of Desired Inventory.