Concept definition 

A constant in PMI Planning is a defined numeric value used to apply a consistent amount or ratio across one or more forecast periods. It’s commonly used for costs or revenues that repeat monthly or follow a stable pattern—like equipment leases or cost ratios.

Using constants helps you streamline forecasting, ensure consistency, and reduce manual effort—especially for accounts that follow predictable trends. 

Formula or logic 

Unlike fixed inputs, constants are defined separately and referenced in planning formulas. You can also customize them by month if values vary during the year. For example, if food cost is usually 30% of food revenue but increases to 40% in December due to a seasonal menu, you can reflect that by adjusting the constant. 

Worked examples 

Example 1: Ratio applied to another value 

You define a constant of 0.30 for “Food cost” and link it to “Food revenue.” 

If December has a different cost ratio, simply assign a separate value (e.g., 0.40) for that month. 

Example 2: Changing mid-year 

You update your equipment lease fee from €1,200 to €1,000 starting in July. 

You only need to update the value once in the constant table—no need to re-enter monthly values. 

What Constant looks like in Planning 

Below are visual steps on how to use constant in the Planning module. For this example, we are adding constant to calculate the food cost. 

1. Go to the P&L page.

2. Under Tools, click Constant. 

3. Click Add constant.

4. Enter the name, profit center, and optional comments. 

Note: In this exercise, we are naming the constant food cost in breakfast. 

5. Tick the Display as percent if preferred. 

Note: The constant is now displayed in the constant table.

6. Click Save/Update. 

Note: After creating the constant, you must reference it in your planning formula. This tells PMI to use your predefined constant in the forecast calculation (e.g., Food revenue × Food cost ratio). 

Now that you’ve seen how constants are used in calculations, here’s how to apply them in the Planning module. 

7. Click the pencil icon next to the account. 

8. Tick the Advanced box.

9. In the Connect/formula field, fill in the formula.

10. Click the wand icon to open the advanced calculation editor. 

11. Choose constant as a source for the “x” value.

12. Choose the type of the constant. 

13. Choose the profit center as a source for the “y” value.

14. Select breakfast as the profit center.

15. Select food revenue as value.

16. Click Save/Update.  

Constants simplify planning by applying consistent values or ratios across months. Whether you’re entering fixed monthly costs or revenue-based calculations, constants help ensure accuracy and reduce manual work. 

Interpretation 

Constants help reduce repetitive work and keep your forecast logic clean. When you expect a steady cost or a known ratio between revenue and cost, constants give you control without micromanaging each month. 

They are also useful for: 

• Adjusting seasonal assumptions 

• Reflecting negotiated contract rates 

• Maintaining a standard ratio across departments or cost types 

Once applied, any updates to the constant automatically reflect in the forecast, ensuring accuracy and saving time. 

Common mistakes 

• Forgetting to update monthly values: If your cost pattern changes, remember to assign different values for specific months. 

• Using percentages incorrectly: If your constant is meant to be a ratio (e.g., 30%), make sure you tick the Display as percent option in the constant table. 

Use cases 

• Fixed monthly expenses (e.g., linen rental, equipment lease) 

• Cost ratios (e.g., food cost = 30% of food revenue) 

• Seasonal adjustments (e.g., December marketing costs = 150% of other months) 

• Rate changes mid-year (e.g., negotiated contract rates that start in July)