System dynamics (stock & flow)

Native Forrester-style system-dynamics diagrams. Stocks render as rectangles, flows as double-line pipes with valves, clouds as source/sink shapes, auxiliaries as circles, and information links as dashed arrows. Used for ecology, economics, public health, and any dynamic systems modelling.

Templates

Source language

plaintext

Workstation

Studio

Engine id

sysdynamics

Open in Studio

In the same space

Most users come to System dynamics (stock & flow) from Stella or Vensim sketches. flowss runs this engine in the browser — no install, shareable via URL, exportable to PNG / SVG / PDF / source.

Syntax at a glance

stock S "Susceptible" at (1,2) initial 990
stock I "Infected" at (4,2) initial 10
flow infection from S to I rate "β·S·I/N"

Paste this in the Studio code pane to see System dynamics (stock & flow) render live. The full grammar is at the upstream-docs link above.

Sample templates

All 10 →

research

System dynamics — SIR epidemic

Classic SIR compartmental model.

research

System dynamics — bathtub stocks + flows

Pedagogical stock + inflow + outflow example.

business

System dynamics — firm growth feedback

Customers + revenue + R&D investment feedback loop.

research

System dynamics — fluid tank with valve

Engineering control example.

research

System dynamics — predator-prey

Lotka-Volterra-style stocks with mutual feedback.

operations

Inventory Control (System Dynamics)

Stocks and flows for an inventory system.

Engine reference: sysdynamics · ← Browse all engines · Quick-start guide