Average on multiple column [period] in a matrix

[AlainMay_68]

Hi all, 

I'm tottaly newby in DAX and need certainly help for a basic commands.

I've got a Matrix that show the data consumption for each mobile subscription, I would like to create a new column to show the average of the data comsuption. 

To built my matrix, I've got 2 tables. 

- DATAs_Vol_Mob

Period	Subscription	DATA Volume
1.2024	4179xxxyy01	8935.663
1.2024	4179xxxyy02	8301.548
2.2024	4179xxxyy01	9035.663
2.2024	4179xxxyy02	8401.548
2.2024	4179xxxyy01	9035.663
3.2024	4179xxxyy02	8386.548

- Inventaire_Mobile

Contrat lié	Référence du contrat	Utilisateur (login)
4179xxxyy01	NATEL® go flex Swiss premium XS	USER#1
4179xxxyy02	NATEL® go flex Swiss premium M	USER#2

A link between the 2 tables in 

The result I want should be :

Utilisateur (login)	Référence du contrat	Subscription	1.2024	2.2024	3.2024	TOTAL	Average [based on all period]	Average of the data consumption of all subscrption of the "Reference du contrat)
USER#1	NATEL® go flex Swiss premium XS	4179xxxyy01	8935.663	9035.663	9035.663	27006.99	9002.33	?
USER#2	NATEL® go flex Swiss premium M	4179xxxyy02	8301.548	8401.548	8386.548	25089.64	8363.21	?

Average [based on all period] = Average of the 3 current period (1.2024 | 2.2024 | 3.2024). Next periods will be added later on. 

Last column should be the average of all subscription per "reference contrat" as I have ~1500 subsriptions. 

I tried to use "Quick Mesure" but the result is not the one I want.

I want also update all month the data for the current period, as I will run this repport on a long terms, having average per year will be a must. 

Thanks for your futur support

[jgeddes · Accepted solution]

Based on what you wrote I think you are looking for something like this...

I have attached a pbix file that shows the measures I used.

Hope this gets you pointed in the right direction.