Posted by Ralf Lippold <ralf_lippold@web.de>
Jay's posting shows that the underlying problem is always essential to a qualitative and quantitative model discussion.
Due to my personal background I can say that in machinery maintenance it is essential to take the materials from stock in FIFO (first in - first out), because some materials are getting sour after a while and can't be used in the machinery any longer. The maintenance and storing policy can be quite different to that and has a significant effect on financial aspects as well.
@John, you are right in making the point that inventory pile up is equivalent to WIP (work in process). That's by the way the connection where SD gets close to Lean thinking where one tries to minimize the WIP through elimation of MUDA (non-value-adding activity in a process).
Best regards from Leipzig
Ralf
Posted by Ralf Lippold <ralf_lippold@web.de> posting date Sat, 28 Apr 2007 16:20:35 +0200 _______________________________________________
QUERY Age of material in a stock
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Ralf Lippold <ralf_lippold@we
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""Douglas Franco"" <dfranco@c
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Posted by ""Douglas Franco"" <dfranco@cantv.net>
his is an extremely simple, but real case.
A company sells appliances in a poor neighborhood by monthly payments, salesperson were door-to-door ones, and they also collect bills. They receive 2% for each bill collected. The stock of collectables has increased 50 %.( a significant portion due to high inflation). Therefore, there was an appreciation by the store managers, of high delay in collections. The wrong measure of the stock of outstanding bills, suggest a change of policy, which consist in giving an extra 2% for any due bill collected. Managers want to diminish due bills. As a result, the stock of bills to collect jumped 400% in two months, because salespersons wait for every bill to be due, before collecting them, to get the 4% commission. The wrong measure of a delay, lead to an intuitive policy even worse, which lead to catastrophe.
Subject:REPLY Zimbardo lecture (SD6399)
From: Tom Cavin <cavin@MIT.EDU>
Date: Thu, 17 May 2007 02:01:39 -0400
To: System Dynamics Mailing List <sdmail@lists.systemdynamics.org>
Hi All,
I just saw the Zimbardo lecture video, and while I found it informative, interesting and gratuitously disturbing, I also found it to be incomplete in the sense that Zimbardo didn't seem to want to follow through with his own argument as he went up the chain of command. He is essentially making the argument that about 90% of our behavior is situationally determined.
The lecture argues the case that although the guards in Abu Ghraib did horrific things, what they did was due more to the situation they were in rather than any guard's inherent moral failure.
Zimbardo argues that the initial statements about ""bad apples"" are unproductive in light of current understanding of social psychology and counters that this was a ""bad barrel"". He also makes the point that the intent to ""get to the bottom of this"" means we'll never ""get to the top"".
Zimbardo argues that the horrors of Abu Ghraib were inevitable given the situation, and focuses the blame for the situation on George W. Bush, <b>****</b> Cheney, Donald Rumsfeld and George Tenet. He makes a very good case for the situation being directly due to the actions of these men, but it seems to me that he then falls into exactly the same trap that he has just been detailing by pointing the finger at this new set of ""bad apples"".
I find Zimbardo's arguments with respect to the guards compelling, and that brings me to the question of understanding the situation of the four men he singles out as ultimately responsible. What are the characteristics of the situation that cause these four men to act in ways that bring about Abu Ghraib and other tragedies? How could our congress have passed laws that limit some of our fundamental rights that are supposed to be guaranteed by our constitution? What is the structural nature of our society that encourages the creation of ""bad barrels""?
It seems to me that many of our social ills are due to ""the system"" and Zimbardo's research supports this notion. If 90% of what we do is determined by ""the system"", then it is highly likely that our ""leaders"" are similarly influenced by their own situation. If that's the case, then changing leaders without changing ""the system"" is not likely to be very effective. Yet changing ""the system"" without first understanding it is also likely to be ineffective simply because ""the system"" is complex.
This is the obvious moment to introduce an SD model of the situation as a whole, describe the various links with their justifications, demonstrate that the model does reproduce the undesirable behavior, and then provide an analysis of possibly more desirable alternatives. However, I don't have such a model. I do have some ideas, but I haven't yet transfered those ideas from wetware to software. Before I do so, I'd like to know if anyone else feels the same way I do about Zimbardo's arguments.
Do you think Philip Zimbardo is correct in attributing 90% of our
behavior to the situations we are in?
Do you think Philip Zimbardo's arguments could be applied to the
behavior of the four people he identifies as ultimately responsible for
Abu Ghraib?
Do you think SD is an appropriate tool for the analysis of this aspect of
our society?
I would greatly appreciate knowing the reactions of other SDers to Zimbardo's ideas and how they might apply to our larger social systems.
Best Wishes,
--Tom
Posted by ""Douglas Franco"" <dfranco@cantv.net> posting date Wed, 16 May 2007 15:12:52 -0400 _______________________________________________
his is an extremely simple, but real case.
A company sells appliances in a poor neighborhood by monthly payments, salesperson were door-to-door ones, and they also collect bills. They receive 2% for each bill collected. The stock of collectables has increased 50 %.( a significant portion due to high inflation). Therefore, there was an appreciation by the store managers, of high delay in collections. The wrong measure of the stock of outstanding bills, suggest a change of policy, which consist in giving an extra 2% for any due bill collected. Managers want to diminish due bills. As a result, the stock of bills to collect jumped 400% in two months, because salespersons wait for every bill to be due, before collecting them, to get the 4% commission. The wrong measure of a delay, lead to an intuitive policy even worse, which lead to catastrophe.
Subject:REPLY Zimbardo lecture (SD6399)
From: Tom Cavin <cavin@MIT.EDU>
Date: Thu, 17 May 2007 02:01:39 -0400
To: System Dynamics Mailing List <sdmail@lists.systemdynamics.org>
Hi All,
I just saw the Zimbardo lecture video, and while I found it informative, interesting and gratuitously disturbing, I also found it to be incomplete in the sense that Zimbardo didn't seem to want to follow through with his own argument as he went up the chain of command. He is essentially making the argument that about 90% of our behavior is situationally determined.
The lecture argues the case that although the guards in Abu Ghraib did horrific things, what they did was due more to the situation they were in rather than any guard's inherent moral failure.
Zimbardo argues that the initial statements about ""bad apples"" are unproductive in light of current understanding of social psychology and counters that this was a ""bad barrel"". He also makes the point that the intent to ""get to the bottom of this"" means we'll never ""get to the top"".
Zimbardo argues that the horrors of Abu Ghraib were inevitable given the situation, and focuses the blame for the situation on George W. Bush, <b>****</b> Cheney, Donald Rumsfeld and George Tenet. He makes a very good case for the situation being directly due to the actions of these men, but it seems to me that he then falls into exactly the same trap that he has just been detailing by pointing the finger at this new set of ""bad apples"".
I find Zimbardo's arguments with respect to the guards compelling, and that brings me to the question of understanding the situation of the four men he singles out as ultimately responsible. What are the characteristics of the situation that cause these four men to act in ways that bring about Abu Ghraib and other tragedies? How could our congress have passed laws that limit some of our fundamental rights that are supposed to be guaranteed by our constitution? What is the structural nature of our society that encourages the creation of ""bad barrels""?
It seems to me that many of our social ills are due to ""the system"" and Zimbardo's research supports this notion. If 90% of what we do is determined by ""the system"", then it is highly likely that our ""leaders"" are similarly influenced by their own situation. If that's the case, then changing leaders without changing ""the system"" is not likely to be very effective. Yet changing ""the system"" without first understanding it is also likely to be ineffective simply because ""the system"" is complex.
This is the obvious moment to introduce an SD model of the situation as a whole, describe the various links with their justifications, demonstrate that the model does reproduce the undesirable behavior, and then provide an analysis of possibly more desirable alternatives. However, I don't have such a model. I do have some ideas, but I haven't yet transfered those ideas from wetware to software. Before I do so, I'd like to know if anyone else feels the same way I do about Zimbardo's arguments.
Do you think Philip Zimbardo is correct in attributing 90% of our
behavior to the situations we are in?
Do you think Philip Zimbardo's arguments could be applied to the
behavior of the four people he identifies as ultimately responsible for
Abu Ghraib?
Do you think SD is an appropriate tool for the analysis of this aspect of
our society?
I would greatly appreciate knowing the reactions of other SDers to Zimbardo's ideas and how they might apply to our larger social systems.
Best Wishes,
--Tom
Posted by ""Douglas Franco"" <dfranco@cantv.net> posting date Wed, 16 May 2007 15:12:52 -0400 _______________________________________________
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""Douglas Franco"" <dfranco@c
- Junior Member
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- Joined: Fri Mar 29, 2002 3:39 am
QUERY Age of material in a stock
Posted by ""Douglas Franco"" <dfranco@cantv.net>
Dear Fred,
There was a perception of an excess of past due bills, because the increase in sales and inflation raise those numbers and the fraction of due bills increases. Inflation increases payments' defaults, because appliances were more expensive and salaries do not increase at the same pace. Therefore, managers perceive an increase in the overall delay of collecting bills. You know the rest of the story. It is unbelievable how people do not understand the kind of things obvious to any System Dynamicist; but even a bathtub seems confusing for most people. The store was sued by providers, because they could not pay on time,
the owner of the store was treated at the unit of intensive care of a local hospital, because a nervous and heart breakdown.
To most managers, in my experience, even simple measures like Stock divided by Average collection rate, are beyond their comprehension.
Douglas Franco
Posted by ""Douglas Franco"" <dfranco@cantv.net>
posting date Thu, 17 May 2007 18:11:40 -0400
_______________________________________________
Dear Fred,
There was a perception of an excess of past due bills, because the increase in sales and inflation raise those numbers and the fraction of due bills increases. Inflation increases payments' defaults, because appliances were more expensive and salaries do not increase at the same pace. Therefore, managers perceive an increase in the overall delay of collecting bills. You know the rest of the story. It is unbelievable how people do not understand the kind of things obvious to any System Dynamicist; but even a bathtub seems confusing for most people. The store was sued by providers, because they could not pay on time,
the owner of the store was treated at the unit of intensive care of a local hospital, because a nervous and heart breakdown.
To most managers, in my experience, even simple measures like Stock divided by Average collection rate, are beyond their comprehension.
Douglas Franco
Posted by ""Douglas Franco"" <dfranco@cantv.net>
posting date Thu, 17 May 2007 18:11:40 -0400
_______________________________________________
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""Fred Nickols"" <nickols@att
- Junior Member
- Posts: 3
- Joined: Fri Mar 29, 2002 3:39 am
QUERY Age of material in a stock
Posted by ""Fred Nickols"" <nickols@att.net>
Douglas Franco provides an example of how incentives can confound a situation.
>> A company sells appliances in a poor neighborhood by monthly
>> payments,
In the example above, Douglas asserts the existence of a ""wrong measure of the stock of outstanding bills."" I'm curious. Could you please say some more about (a) what the measure was and (b) why it was the ""wrong"" measure?
I ask because I can see quite clearly from the example how the incentive could lead to an increased stock of due (overdue or past due?) bills, but I don't quite see what the measure was or why it was the wrong one.
Thanks...
Fred Nickols
Posted by ""Fred Nickols"" <nickols@att.net> posting date Thu, 17 May 2007 09:07:30 -0400 _______________________________________________
Douglas Franco provides an example of how incentives can confound a situation.
>> A company sells appliances in a poor neighborhood by monthly
>> payments,
In the example above, Douglas asserts the existence of a ""wrong measure of the stock of outstanding bills."" I'm curious. Could you please say some more about (a) what the measure was and (b) why it was the ""wrong"" measure?
I ask because I can see quite clearly from the example how the incentive could lead to an increased stock of due (overdue or past due?) bills, but I don't quite see what the measure was or why it was the wrong one.
Thanks...
Fred Nickols
Posted by ""Fred Nickols"" <nickols@att.net> posting date Thu, 17 May 2007 09:07:30 -0400 _______________________________________________