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Posts Tagged ‘Causal Loop’

Drifting Goals

March 9th, 2016 No comments

The Drifting Goals Archetype applies to situations where short-term solutions lead to the deterioration of long-term goals.  Also known as Eroding Goals, this is a special case of Shifting the Burden.  This Systems Archetype was formally identified in Appendix 2 of The Fifth Discipline by Peter Senge (1990).  The Causal Loop Diagram (CLD) is shown below.

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When a gap exists between the current state of the system and our goal (or desired state), we take action proportional to the gap to move the system state toward our goal.  There is always a delay between the action we take and the effect on the system.  Simultaneously, pressure is exerted to instead adjust the goal to close the gap.  Adjusting the goal leads to a situation where the goal floats independently of any standard.  It often leads to goals being reduced, or eroded.

Classic examples of drifting goals include:

  • Reducing quality targets to improve measured quality performance (relative to goal) or to improve delivery schedule
  • Reducing quality of ingredients or parts below company standards to improve profits
  • Increasing time to deliver to match existing capacity and save on overtime
  • Reducing a new product’s feature set to meet deadlines; this works the other way also, i.e., extending the deadline to include all of the features
  • Reducing pollution targets when reduction implementation costs are too high
  • Increasing budget deficit limits rather than decreasing spending (or increasing taxes)
  • Adapting to unacceptable social circumstances rather than leave that environment
  • Reducing entrance requirements because not enough applicants meet them
  • Reducing level of patient care below recommended minimum due to understaffing
  • Reducing margin to spur sales and meet revenue targets
  • Lowering your own expectations in life, leading to lower personal success

Note that in many of these cases, there are competing goals and one is held more sacred than another.  Drifting Goals is an insidious process that seeks to lower your standards to the level of the current state of the system.  Stay aware of not just how the state of the system adjusts to your goal, but also of how your goal varies over time.  Changing a goal should be a conscious decision that does not undermine other objectives.

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Shifting the Burden

December 22nd, 2010 3 comments

The Shifting the Burden Systems Archetype shows how attacking symptoms, rather than identifying and fixing fundamental problems, can lead to a further dependence on symptomatic solutions.  This Systems Archetype was formally identified in Appendix 2 of The Fifth Discipline by Peter Senge (1990).  The Causal Loop Diagram (CLD) is shown below.

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When a problem symptom appears, two options present themselves:  1) apply a short-term fix to the symptom, or 2) identify and apply a longer-term fix to the fundamental issue.  The second option is less attractive because it involves a greater time delay and probably additional cost before the problem symptom is relieved.  However, applying a short-term fix, as a result of relieving the problem symptoms sooner, reduces the desire to identify and apply a more permanent fix.  Often the short-term fix also induces a secondary unintended side-effect that further undermines any efforts to apply a long-term fix.  Note that the short-term fix only relieves the symptoms, it does not fix the problem.  Thus, the symptoms will eventually re-appear and have to be addressed again.

Classic examples of shifting the burden include:

  • Making up lost time for homework by not sleeping (and then controlling lack of sleep with stimulants)
  • Borrowing money to cover uncontrolled spending
  • Feeling better through the use of drugs (dependency is the unintended side-effect)
  • Taking pain relievers to address chronic pain rather than visiting your doctor to try to address the underlying problem
  • Improving current sales by focusing on selling more product to existing customers rather than expanding the customer base
  • Improving current sales by cannibalizing future sales through deep discounts
  • Firefighting to solve business problems, e.g., slapping a low-quality – and untested – fix onto a product and shipping it out the door to placate a customer
  • Repeatedly fixing new problems yourself rather than properly training your staff to fix the problems – this is a special form known as “shifting the burden to the intervener” where you are the intervener who is inadvertently eroding the capabilities and confidence of your staff (the unintended side-effect)
  • Outsourcing core business competencies rather than building internal capacity (also shifting the burden to the intervener, in this case, to the outsource provider)
  • Implementing government programs that increase the recipient’s dependency on the government, e.g., welfare programs that do not attempt to simultaneously address low unemployment or low wages (also shifting the burden to the intervener, in this case, to the government)

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Limits to Growth

December 3rd, 2009 5 comments

This is the first of a three-part series on the Limits to Growth Archetype.  The second part can be accessed here and the third part here.

The Limits to Growth Systems Archetype, also known as Limits to Success, combines growth with an exogenous or endogenous limit.  This Systems Archetype was formally identified in Appendix 2 of The Fifth Discipline by Peter Senge (1990), but made its first prominent appearance in World Dynamics by Jay Forrester (1971) and then The Limits to Growth by Meadows, Meadows, Randers, and Behrens (1972).  The Causal Loop Diagram (CLD) is shown below.

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Real growth processes have inherent limits to growth.  Identifying these limits can help avoid problems in the future, whether the problem is overpopulation, increasing demand for a product that cannot be met, or growing a business in a mature market.  When growth is desired, but limited, it is always better to find ways to increase the limit before pushing for more growth.  Excessive growth in the face of a limit often leads to collapse.  Driving the system to the point of collapse can erode the ability to continue after the collapse, for example, by reducing the production capability of a piece of farmland or destroying the reputation of a company.

Classic examples of limits to growth include:

  • The collapse of the deer population on the Kaibab plateau and on St. Matthew Island due to overpopulation and the attendant overgrazing of their habitat
  • The overshoot and collapse of the human population on Easter Island
  • Overgrazing in the Sahel region of Africa by cattle herders
  • Overfishing of the oceans by fishermen
  • The collapse of People Express due to sharp customer growth combined with slow personnel growth
  • The sharp exodus of America Online subscribers after an intense marketing campaign increased the number of subscribers far beyond their capacity
  • The contraction of the world economy in 2008 due to limiting oil supplies
  • The productivity of staff deteriorating as a company grows, due to increased interactions and reporting overhead
  • Business growth limited by the size of the potential market
  • Yeast cells in the fermentation process, who suffer from both the loss of exogenously supplied sugar and the increase of endogenously produced pollution

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Success to the Successful

July 15th, 2009 No comments

fifth_disciplineMy first introduction to the Systems Archetypes was years ago when I read Peter Senge’s book, The Fifth Discipline.  I remember relating these classic Systems Thinking stories to my own experience in business and thinking how useful it was to understand some of the problems we faced and why solutions didn’t always work out as intended.

What I’ve come to appreciate since then is how the characteristic themes of the Systems Archetypes transform across all sorts of different fields and situations — even our personal lives!

Take, for example, the basic story line of the “Success to the Successful” archetype:

When given the choice, we invest our resources where we expect them to deliver the best results.  By giving more resources to one option over another, we create a self-fulfilling prophesy whereby the favored option is perpetually more successful.

The story of the Success to the Successful archetype applies to all sorts of  situations leading to well-known patterns of behavior:

Exploring the Model Structure

We recently published a model of the Success to the Successful archetype to the web using isee NetSim. Exploring the model is a great way to understand the underlying structure of the Causal Loop Diagramsystem and think about ways to avoid the problems it creates.

You’ll also get an appreciation of how the decision policy for allocating resources can determine success rather than competence.

Running the Simulation

After you’ve explored the model, try running a simulation.  The base case scenario assumes no one has an advantage over the other.  As you can imagine, everyone is equally successful and it’s a win-win situation.  Try turning on the “Advantage A Switch”  to see how even a modest advantage for A can snowball into a disadvantage for B.  It’s surprising how quickly the gap can widen.

Using Modules to Create Models

In STELLA and iThink version 9.1, we added the ability to build models by linking together modules.  The Success to the Successful model is an example of how you can use modules to create a higher level map of your model.  This map can easily be presented as a causal loop diagram.

The beauty of modules is they simplify the process of transitioning from a CLD to a model that actually simulates.  If you’ve ever tried to convert a causal loop diagram into a stock and flow model, you can appreciate what I’m talking about!  By architecting your model into modules, you’ve got a built-in mechanism for developing your model in manageable chunks and communicating the high level causal relationships.

Insight-based Model Investigates the Housing Crisis

May 5th, 2009 3 comments

wpi-logoFor the past few months I’ve been taking a distance learning course at WPI called “System Dynamics Foundations: Managing Complexity”. The course covers a broad range of topics about the system dynamics methodology and how it has been applied in the real world.

One of the things I really like about the course is the different perspective the instructors bring to the table (or in this case my computer screen.) Last week’s lecture focused on three different styles of system dynamics modeling – Causal Loop Diagrams (CLDs), insight-based models and calibrated models.  While both instructors agreed there is value in all three approaches to dynamic modeling, there was clearly a difference of opinion about what is required to actually DO something with a proposed solution to a problem.

The topic got me to thinking about the types of STELLA and iThink models that are being built and how they are being used to DO something about real world problems. I would guess that the majority of the models fall into the insight-based category.   One of the reasons we put so much effort into creating communication features in our software is so that those insights can be shared and discovered by others.  The “ah-ha” moments that come from experimenting with simulations are often a great vehicle for getting conversations going about a particular issue and discussing possible solutions.

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