TM1 Rules - Linking multiple source cubes into one target cube

Question

I have two (so far) source cubes and their respective dimensions:
EXPENSE: Date1, Date2, Supplier, Cost/Profit Center, Project, Type of Payment, Measures.
INCOME: Date1, Date2, Subcontractor, Customer, Cost/Profit Center, Project, Type of Payment, Measures.

I want to use the above mentioned cubes as a source for a third cube:
FINANCE: Date1, Cost/Profit Center, Project, Type of Payment, Measures.


The dimension Cost/Profit Center is used is each of these cubes and has following structure:

TOTAL
--EXPENSE
---10000 - Consulting
----11000 - Personal Expense
-----11100 - Sallary
------11101 - Gross Salary*
------11102 - Bonus*
...
--INCOME
---2000 - Services
----2100 - Projects
-----2110 - Support
------2111 - Support for ABC*
------2112 - Support for XYZ*
...

(*) Leaf elements

The goal is to load data from EXPENSE cube into FINANCE cube under Expense, and from INCOME cube to FINANCE cube under Income.
How do I define the rule without manually linking the corresponding leaf level members? I am looking for something like

['TOTAL':'Expense'] = N:DB(... data from Expense cube)
['TOTAL':'Income']  = N:DB(... data from Income cube)

So far I came up only with one solution which works although I am quite sure it is not the right approach:

[] = N: DB('Expense', '...) + DB('Income', '...)

Thanks a lot!

Answer 1

Using DB is of course required for any link between two cubes. Having said that, depending on your version of TM1, if performance modeller is available, creating graphical links is probably the easiest way to get the job done. It creates the rules in the respective cubes rule files so it is also a good learning tool.

To the essence of your question, as a high level view, let's assume that TM1 calculates the cube by running through its cells. Each cell is defined by members for all dimensions specified. When you rule something, the !Date1 variable (i.e. ! in front of the Date1 dimension name) gives you the member for the Date1 dimension of the current cell. Therefore, given that your Cost/Profit Centre dimension is the same, shared across cubes (not optimal and it should probably be Account) you can map one leaf element to the other (!Account).

For dimensions that you have in the source cube, but not in the target, you have to create a total element to use in the DB.

Finally, whatever rule you create to pull data in your Finance cube, you also have to create a feeder in your respective source cube.