Skip to main content

​
Overview

Models are the core building blocks in Veydra. Each model represents a system dynamics simulation that captures the structure and behavior of real-world systems through stocks, flows, and feedback loops.

​
Creating a New Model

You can create a new model in several ways:

​
From the Dashboard

  1. Navigate to your Dashboard
  2. Click + New Project to create a new project with a model
  3. Configure your model settings and click Create

​
From an Existing Project

  1. Open your project from the Dashboard
  2. In the Models & Activities section, click + New Model
  3. Your new model will be added to the existing project
Creating models within an existing project helps organize related simulations and share team access.

​
From the Library

  1. Browse the Model Library for existing models
  2. Click Fork on any public model
  3. A copy will be created in your workspace that you can modify

​
Model Components

Every model consists of several key elements:

Stocks

Accumulations that represent the state of your system (e.g., Population, Inventory, Capital)

Flows

Rates of change that increase or decrease stocks over time

Parameters

Constants and coefficients that control model behavior

Auxiliaries

Calculated variables that depend on stocks and parameters

​
Model Settings

Model editing is split into two scopes so it is clear what you are configuring:

​
Model-Level Settings

These settings belong to the model entity itself:
  • Title: Display name for your model
  • Description: Brief explanation of what the model represents
  • Model Status: Lifecycle state for the model (draft, active, completed, archived)
  • GitHub Integration: Link or manage the model repository
  • Activities List: Create, edit, and manage attached activities

​
Default Playground Settings

These settings are edited on the dedicated Playground Settings page for a model and control the default playground experience:
  • Default mode for the model playground
  • Available modes in the default playground
  • Library/discoverability settings (include in library, access level, complexity, category, tags)
Use these defaults when users open the model playground without selecting a specific activity.

​
Simulation Settings

  • Time Horizon: How far into the future to simulate
  • Time Step (DT): Granularity of calculations
  • Integration Method: Euler or Runge-Kutta

​
Activities

Models can have multiple Activities attached to them. Activities provide interactive scenarios where users can manipulate parameters and compete to achieve goals. Activity statuses are independent from the model lifecycle status. See Activities for more details.

​
Model Workflow

1

Design

Build your model structure in Design Mode using the stock-flow diagram editor and code panel
2

Test

Run simulations in Experiment Mode to verify behavior matches expectations
3

Calibrate

Fine-tune parameters to match real-world data using built-in calibration tools
4

Share

Publish your model to the library or share directly with collaborators

​
Best Practices

Name your stocks, flows, and parameters clearly. Future you (and your collaborators) will thank you.
Use the model description and comments to explain key assumptions and data sources.
Create new model versions when making significant changes to preserve previous states.
Share your model with colleagues to catch errors and improve clarity.