System archetype

Systems & feedbackField guide · Systems & feedback · 6 of 6

Which stories play out again and again?

Over the causal loop diagram’s marks, a system archetype shows a declared archetype, one line of words, and roles above variables’ names.

Marks

• variable

• effect

• polarity

• delay

• loop

• reinforcing loop

• balancing loop

• boundary

• external driver

• gapdrawn as an ordinary variable

• nonlinear effect

• evidence coding

• leverage point

• behavior note

• viewpoint tag

• archetype

• symptomatic solutiona role, written above its variable's name

• fundamental solutiona role, written above its variable's name

• side effecta role, written above its variable's name

How each mark is drawn and read: chapter 10, What the notation expresses.

A line with an arrowhead

A line with an arrowhead is an effect, as in a causal loop diagram: a change in the variable at its tail causes one in the variable at its head, its polarity giving which way.

Spraying a valley’s rice

Spraying, the symptomatic solution, lowers pests in B1 fewer pests; through its side effect, natural predators, and a delay, R1 pests return brings them back: the loops of the declared archetype, fixes that fail (chapter 10’s valley).

When to draw one

Draw one when a fix worked at first and the problem came back worse, when growth slowed while the effort behind it kept rising, or when a situation’s loops sound like a story from somewhere else (chapter 10’s signals).

When not to draw one

Whether these predators eat these pests is a question for evidence, not for matching. How late a delayed change arrives, and why and how hard to act at a leverage point, go in a behavior note or prose beside the diagram (chapter 10, what stays informal).

Reasoning and polish

• Reasoning5 of 5
• Polish4 of 5archetype trace → leverage story

1. Match a diagram's loops to one archetype
2. Adapt the structure and check every effect
3. Compare archetypes, side effects, delays and leverage points

Related types

• A system archetype is drawn with a causal loop diagram’s marks, with roles and a declared archetype written on it.

In this book

• Chapter 10, Structures That Recur: matching, symptomatic and fundamental solutions, side effects, five archetypes and a variable named as its opposite; exercises AR 01–05.
• Chapter 11, Diagnosing Tangled Situations: four more archetypes, one structure read as two stories, coupled archetypes and ranking leverage; exercises AR 06–10.

Sources

• Daniel H. Kim, Systems Archetypes I: Diagnosing Systemic Issues and Designing High-Leverage Interventions (Pegasus Communications, 1992, 2000): the archetypes used as templates, p. 2; Peter Senge’s The Fifth Discipline (1990) as the source of the term, p. 3; growth and underinvestment, pp. 6 and 18–19; eroding goals, pp. 12–13; escalation, pp. 14–15; fixes that fail, pp. 16–17; limits to growth, pp. 20–21; shifting the burden, pp. 22–23; success to the successful, pp. 24–25; the tragedy of the commons, pp. 26–27.
• Jennifer Kemeny, “‘Accidental Adversaries’: When Friends Become Foes”, The Systems Thinker 5, no. 1 (February 1994): 5–6, on partners whose corrective measures obstruct each other.
• Lukas Schoenenberger, Alexander Schmid and Markus Schwaninger, “Towards the Algorithmic Detection of Archetypal Structures in System Dynamics”, System Dynamics Review 31, no. 1–2 (2015): 66–85, on algorithms that find archetypes in simulation models.