Hi LeanIX Community,

I'm trying to implement a cost allocation model using custom fields and calculations, but I’ve run into an issue.

Scenario:
I’ve created a custom field (Application Cost) on the Application Fact Sheet (type: Double, displayed as Cost), and I also have a field (Number of Users) on the Application–Organization relation. The idea is to calculate the proportional cost per organization, based on how many users are using the application within each connected organization.

Example:

Application cost: €50,000/year

Org A: 700 users

Org B: 5 users

Org C: 300 users
→ Total = 1005 users

I want to calculate a new value (e.g. Chargeback) on the Application–Organization relation as:(application cost / total number of users) × users per org

Issue:
I created a new Double field on the Application–Organization relation to store the Chargeback value, but when I try to create a Calculation in the Admin interface, this field doesn’t appear as a selectable target — even though it is visible, active, and of type Double.

Question:

Has anyone successfully created a calculation that targets a custom relation field (e.g. between Application and Organization)?

Are there any known reasons why such a field would not appear in the dropdown when configuring a Calculation?

Is there another way to achieve this type of cost distribution across organizations using LeanIX?

Thanks in advance for any guidance or workarounds you can share!