Model Formatting
Here's how I use formatting to identify and denote the difference between assumptions and calculations in the models.
A consistent formatting scheme makes it easier to understand how a model is structured at a glance. Once you've designed your spreadsheet layout, a color scheme helps you communicate how the model works.
Common conventions
A common convention used by many modelers:
- Blue font for inputs
- Black font for calculations
- Green font for numbers pulled in (imported) from another sheet
FAST Standard
The FAST Standard adds two notes on color:
- Mark exports with red font and imports with blue font (FAST 1.01-06)
- Mark intra-sheet counter-flows with grey shade (FAST 2.01-05)
Hemrock models
Hemrock models use two conventions:
- Blue font with light grey background for inputs
- Black font for calculations
The grey shaded background makes the input cell feel more like a form field in a website or web app, and is easier to read than a red, yellow, or green shaded background.
Green font for imports and red font for exports is skipped in Hemrock models, because extensive sheet-to-sheet linking would make the formatting too distracting.
A shared language is valuable, and clearly explaining the color formatting used in the model is critical. A model without any font colors or shading is much harder to use - color is an effective signal for what different components do.
Hemrock models note the color convention in their README sheets. You're free to alter the formatting to fit your needs. The models are styled to be clean and minimal, so it's easy to add your own formatting to highlight what you want.