methodatlas
RunsheetSystems Thinking

Causal Loop Diagram

ComplexityMedium
Time1-3 h
Participants2-8
FormatWorkshop
MaturityEstablished
01

Prerequisite

What needs to be finished first

Complete firstIceberg Model

There are signs of recurring patterns or structures that go beyond individual events.

Without: Without signs of structural patterns, the CLD becomes a causal chain without feedback and is redundant to 5 Whys.
Complete firstVariable listnot in catalog

A first list of relevant variables with a clear direction (more or less) is prepared, so the model starts with substance.

Without: Without variables, the workshop has to do definition work, and diagram quality stays low.
02

Preparation

What needs to be ready before start

Materials

Whiteboard or Miro board; arrows with polarity (+/-) and loop labels (R for reinforcing, B for balancing); notation cheat sheet visible; prepared variable list.

People / roles

One facilitator with a systems-thinking background; 3-6 participants with different system knowledge; one model writer who sets arrows consistently; optional domain expert.

Pre-read

Data points or reports that show the suspected behavior over time; relevant hypotheses about causes; existing quick fixes and their (failed) success.

Time needed

2-4 h

Setup

Notation legend visible: arrow with + means same direction (more A -> more B), arrow with - means opposite direction. R loops reinforce, B loops balance. Rule: every variable is a measurable quantity, not an adjective.

03

Core question

The one question this method answers

Which feedback loops create the observed behavior, and which leverage point inside the system shifts it sustainably?

04

Flow

Marker: Phase

StepDurationActionHint
1Phase 1: Behavior over time
30 minSketch the reference mode: show the behavior of the key variable over time as a graph (past plus expected future). Draw both observed and desired behavior.If nobody can sketch the behavior over time, data is missing. A model without a reference mode becomes theory without grounding.
2Phase 2: Collect variables
30 minOne card per variable. Variables are measurable (count, rate, share), not qualities. 'Motivation' becomes 'approval rate per survey'. About 8-15 variables.If variables are not formulated in a measurable way, the model produces unclear arrows. Minimum standard: I could theoretically quantify the variable.
3Phase 3: Causal arrows
60 minDraw arrows between variables, each with a sign. Test: if A increases, what happens to B, all else equal? Only direct causality, no multi-step jumps.If an arrow is uncertain, mark the assumption with a question mark. Multiple steps between A and B often hide variables that need to be added.
4Phase 4: Identify loops
45 minFind closed loops. For each loop multiply the signs: even number of minus signs = R (reinforcing), odd number = B (balancing). Note loop label and character (growth, stabilization, delay).Identify the central loops when there are several. If only reinforcing loops appear, balancing mechanisms are missing and the system would explode or collapse.
5Phase 5: Leverage points and interventions
30 minDiscuss leverage points per top loop (Donella Meadows: parameters, loop strengths, loop structure, goals, paradigms). Sketch one concrete intervention per leverage point.Parameter changes are the lowest leverage level. If all interventions are parameters, the facilitator asks for structure- or goal-related leverage points.
05

Artifact

What comes out at the end

Form

Causal Loop Diagram as an image plus a Markdown companion document with reference mode, variable list, arrow list with signs, loop description (R/B, effect), identified leverage points, and intervention sketches.

Versioning / ownership

One version per iteration with date. Document model changes with justification. Mark hypothesis arrows separately from validated arrows so model quality stays visible.

Tool alternatives
  • Miro or FigJam with a custom notation
  • Kumu for interactive loop visualization
  • Vensim or Stella for formal simulation
  • Loopy (ncase.me/loopy) for animated models
  • draw.io or Lucidchart with a system dynamics library

causal-loop-diagram-working-template.md

Compact working template for Causal Loop Diagram with context, input, output artifacts, and next step.

Causal Loop Diagram Canvas

Context

What is this method used for?

Core question

Which question should be answered at the end?

Input

Which data, observations, or materials are available?

Working area

  • Area 1:
  • Area 2:
  • Area 3:
  • Relationships / patterns:

Output artifacts

  • Causal Loop Diagram:
  • Feedback Notes:
  • Leverage Points:

Open questions

  • ...

Next step

Owner, date, success signal.

06

Example output

Concrete filled scenario, fictional example

causal-loop-diagram-beispiel.md

Concrete filled scenario, fictional example

Causal Loop Diagram - Onboarding workspot, May 2026

Observed behavior: Activation rate rises briefly after a marketing push, then falls below the prior period. The reference mode shows a sawtooth pattern (spike, drop, spike, drop).

Variables (excerpt)

  • A: New sign-ups per week
  • B: Onboarding wait time for Customer Success (hours)
  • C: Activation rate (value per sign-up)
  • D: Month-1 churn rate
  • E: Customer Success capacity
  • F: Marketing budget per quarter

Causal arrows

  • F -> A (+): More budget means more sign-ups.
  • A -> B (+): More sign-ups lengthen wait time (CS capacity fixed).
  • B -> C (-): Longer wait time reduces activation.
  • C -> D (-): Lower activation increases month-1 churn.
  • D -> F (+): Higher churn creates pressure to increase marketing for replacement users.

Loops

  • R1: F -> A -> B -> C -> D -> F. Reinforcing loop 'churn spiral': more marketing creates more churn, which justifies more marketing. Main cause of the sawtooth.
  • B1: E -> B (-). Balancing, but E does not change.

Leverage points

  • Weaken loop strength: couple CS capacity (E) to A in a flexible way.
  • Change the goal: not 'more sign-ups' but 'more activations'.
  • Structure: make onboarding self-serve so B does not depend on E.

Interventions

  • CLD-01: Dynamically couple CS slots to sign-ups. Owner: @lisa.
  • CLD-02: Build self-serve onboarding. Owner: @ben, spike by 30.06.
  • CLD-03: Shift the North Star to activation instead of sign-ups. Owner: @julia (Head of Growth).
07

Pitfalls

Recognize symptoms and steer against them

Trap

Adjectives instead of variables

Symptom

Cards contain 'good mood' or 'complex architecture' without a measurable lever.

What to do

Name a measurement path for each variable, even if rough. If it is not measurable, split the variable. 'Architecture complexity' becomes 'number of modules' or 'cycle time per deploy'.

Trap

Arrows without signs

Symptom

Connections look plausible, but loop analysis is impossible.

What to do

Notation is strict. An arrow without + or - is not accepted. If the direction is unclear, mark a double arrow with a note about delay.

Trap

Model without delays

Symptom

The model suggests immediate effects, and the real dynamics with delay disappear.

What to do

Use delay notation (||) on arrows with a significant time lag. The reference mode often shows delays as waves, which motivates the notation.

Trap

Too many variables

Symptom

The model has 40 variables and 80 arrows, and nobody can find the loops.

What to do

Reduce to 10-15 central variables. Move detail variables to submodels or a notes appendix. Model quality beats completeness.

Trap

Leverage point at parameter level

Symptom

All interventions change only values (more budget, more people), not structure or goals.

What to do

Walk through Donella Meadows' leverage points. Start at least one intervention at the structure or goal level.

08

Stop criteria

Done signals checkable in under a minute

The problem is linear and one-off, with no feedback visible.
Variables cannot be formulated in a measurable way, so the model remains a word cloud.
The reference mode cannot be sketched and the behavior over time is unknown.
The workshop is shorter than 90 minutes, so loops cannot be identified cleanly.
Participants insist on solutions, and the model becomes justification instead of diagnosis.
No willingness to address structural leverage points, only parameter optimization is wanted.

Finished the runsheet?

Go to the profile for purpose, similar methods, and sources or continue to the next method in the catalog.