Subject: help in pendulum model

Posted by Bill Braun on 9/30/2008
In Reply To:help in pendulum model Posted by Paul Newton on 9/30/2008

Message:

There are a number of principles in Forrester's "Principles of Systems" that are relevant; I think they can be condensed into Principle 4.3-3 - "Levels are changed only by rates." Unilaterally preventing levels from going negative appears to violate this principle. It is policies that ought to prevent a level from going negative, not an artifact of software programming (so me thinks).

Bill Braun