weighting factor in bridge table

Hai

in the added model I understand the use of a bridge table. But I keep on having trouble understanding the use of a 'weighting factor'.. Can someone explain me in a simple and clear way the use of this attribute in this example?

Thanks
Ron

Weighting factors are used to allocate measures when are multiple targets. Using your model, if the account maps to multiple customers and you wanted to report account snapshots by customer, you would use the weights to porportion measures (such as interest paid) across the customers holding the same account.

Just to add a little report example at this many to many problem.

Without Customer:

Account	Number of Transactions
100000	100
Total	100

With the customer:

Customer	Account	Number of Transactions
The customer 1	100000	100
The customer 2	100000	100
Total	100000	200

As you can see the total is not good, you have to correct it with the weighing factor:

With the weighing factor:

Customer	Account	Number of Transactions	Weighing factor	Number of Transactions Corrected
The customer 1	100000	100	70%	70% x 100 = 70
The customer 2	100000	100	30%	30% x 100 = 30
Total	100000	200	50%	100

Thanks ngalemmo

and what then is, in my example, the difference between impact and weighted report?

Thnx
Ron

gerardnico wrote:

Account	Number of Transactions
100000	100

Customer	Account	Number of Transactions
The customer 1	100000	100
The customer 2	100000	100

Hello, gerardnico, thanks for the reply but I don't know what you are trying to say with this.

Hello,

I was struggling with the table and I have pushed the Send button in place of the preview. I have just modified my previous ticket with the complete example.

Cheers
Nico

gerardnico wrote:Hello,

I was struggling with the table and I have pushed the Send button in place of the preview. I have just modified my previous ticket with the complete example.

Cheers
Nico

Thanks Nico for the example
clear
In the bridge table you have foreign keys of customers and accounts, with their weighting factor
Wehere do I fit in your customer called 'Total' with weighting factor 50%? I mean, do I have to insert a customer called 'Total' then in the customer dimension?
And what is difference between impacted and weighted report?

thnks
Ron

The last line is a total that any report tools can make and doesn't come from your model.
- For account: a max
- For Number of Transactions: a sum
- For weighing factor: an average but as you do the sum, you must have 100%

I think that Impact report is the second example (Do you see the impact, a bad sum)
and weighed report the third (the corrected one)

Cheers
Nico

Great, I understand
but the weighting factor is not an attribute you get from a source system
So how do you compute / determine the weihgting factor for each individual customer?

Ron

The weighting factor is determined:
- of by the business
- of during the load with a calculation.

If you have for the same account:
- two customers, then 50% (100/2)
- three customers , then 33% (100/3)
- etc ...

Cheers
Nico

I have forgotten, it can also be calculate by the reporting tool.
This kind of calculation during a report generation doesn't cost so much.
I work intensively with OBIEE and it's really easy to do as you just have to divide by the total of customer by account.

Cheers
Nico

Ok Nico

but then it doesn't exactly reflect the reality then? It is, as to say indeed a weighted factor? It gives, let's say an indication

Ron

In all cases, it reflects the reality of your data model. You affect proportionally the account metrics to your customers.

If when you say that it reflects not the reality because a transaction has always a customer, I will say that it's more a data modelling problem.

Cheers
Nico