Re-use data transformation and report

Hello Dear Community, 

Here is my scenario: 

The team I work with would like to re-use a transformation I have made on an Excel file for new Excel files with the same structure but different data.

Therefore, they want to re-use the transformation made on the previous Excel file just by changing the source file and get the results updated on the visuals. 

Excels file have 1 or 2 sheets. Therefore, in my data transformation, I created a function to transform the sheet and combine both sheets.

My question is the following: How can I reuse the data transformation and the data modeling whitout having to change the data source in both the fact table and the dim tables of my model? What would be the best solution?would you have any tutoriel? 

(After I made the transformation on the Excel file, I duplicated the main table to get a fact table and few dimension tables. I didn't use referencing. )

Thank you for the help,

Chris