MSAS m2m attribute not resolved as expected - mdx

Question

I'm no expert in MSAS Cube so may be this is obvious, but this is blocking an important feature in our team.
We have a fact table of "Indicators" (basicaly values from a calculator), that are computed for a specific date. indicators have a versionId, to group them following a functional rule.
It goes like :
From Date, Value, NodeId, VersionId
D0 - 1.45 - N2 - V0
We have a fact table of "VersionsAssociation" that lists all the versions (the very same versions as the ones in the "Indicator" fact table) that are valid and visible and for what date.
To fit with a customer need, some versions are visible at multiple dates.
For instance, a version computed for date D0, may be visible/recopied for date D1, D2, ...; so for a specific version V0, we would have in "VersionAssociation" :
VersionId , Date From (computed), Date To (Visible at what date)
V0 - D0 - D0
V0 - D0 - D1
V0 - D0 - D2
V0 - D0 - D3
...
In our cube model, "Indicators" facts have a "From Date", the date they are compute for, but no "To Date", because when they are visible is not up to the indicator, but rather decided by the "VersionAssociation".
The means that in our "Dimension Usage" panel, we have a many-to-many relation from "Indicator" pointing to "VersionAssociation" on the dimension "To Date".
So far, this part works as expected. When we select "To Date" = D1 in Excel, we see indicators recopied from D0, with right values (no duplicate).
Then we have a thing called projection, where we split an indicator value alongside a specific dimension. For that we have a third measure group called "Projection", with values called "Weight".
Weights have a "To Date", because the weight are computed for a specific date, and even if an indicator is copied from D0 into D1, when projected, it is projected using D1 Weights.
Also we duplicate the weight regarding all the available from date, that's strange, but without it, the result are pure chaos.
Meaning we would have in the weights:
NodeId,From Date, To Date, Projection Axis, Weight
N2 , D0 , D0 , P1 , 0.75
N2 , D0 , D0 , P2 , 0.25 (a value on node N2 would be split into 2 different values, where the sum is still the same)
N2 , D0 , D1 , P1 , 0.70
N2 , D0 , D1 , P2 , 0.30
Here goes the issue:
The Measure Group "Projection" and "Indicator" are directly linked to the dimension "Projection".
"Projection" has a direct link to the "From Date" and the "To Date" dimension.
"Indicator" has a direct link to the "From Date" dimension, but only a m2m reference to the "To Date" dimension, through the "Version Association" measure group.
To apply the Projection weights, we use a measure expression on the mesures from the "Indicator" Measure group, having something like "[Value Unit] * [Weight]".
Because of reasons, this causes MSAS to not properly disciminate the weight that are eligible to apply to a certain value in the "Indicator" measure group.
For instance, if we look into excel and ask for the D1 date (same behavior for all date), on the Projection Axsi P1 we got :
Value Weight
1.45 * 0.75 (Weight: From Date D0, To Date D0, P1)
+ 1.45 * 0.70 (Weight: From Date D0, To Date D1, P1)
for D1 and P2 we have :
Value Weight
1.45 * 0.25 (Weight: From Date D0, To Date D0, P2)
+ 1.45 * 0.30 (Weight: From Date D0, To Date D1, P2)
This cause the values to mean nothing and be non readable.
So what all of this is for, is to ask for a way to limit the weights that can be applied in the measure expression. We tried to use scope on "From Date" , "To Date" with the "Weight" measure or the "Value" measure, but the cube never step in our SCOPE instructions.
This is very long, and complicated, but we're stuck.

Answer 1

I am not sure that I understoond your problem completely, but what I understood is that since there is no projection axis in the fact Indicator, hence for a similar FromDate and ToDate, when Projection is selected they repeat values.
example from your data
D0 , D0 , P1 , 0.75
D0 , D0 , P2 , 0.25
for this the indicator value is repeated 1.45 for both rows where as it should be 1.45*0.75 for the first row and 1.45*0.25 for the second.
If this is the issue try the below query
with member Measures.IndicatorTest
as
([DimFromDate].[FromDate].CurrentMember,
[DimToDate].[ToDate].CurrentMember,
[Value Unit])
member Measures.ProjectionTest
as
([DimFromDate].[FromDate].CurrentMember,
[DimToDate].[ToDate].CurrentMember,
[DimProjection].[Projection].CurrentMember
[Weight])
member Measures.WeightedIndicator
as
Measures.IndicatorTest*Measures.ProjectionTest
select Measures.WeightedIndicator
on columns,
nonempty
(
[DimFromDate].[FromDate].[FromDate],
[DimToDate].[ToDate].[ToDate],
[DimProjection].[Projection].[Projection]
)
on rows
from yourCube

Answer 2

For closure, as it turns out the behavior expected is not possible (as far as out team tried). so we reverted to merging two of the 3 tables together, and ahving only one many-to-many join in the measure groups.