​Hi,
I have some questions on using an external data source for creating reports using Cognos analytics.  I am looking to get answers for creating reports using data from just an Excel file (no integration of Excel data with enterprise data / data packages).  The data needs to be refreshed on a daily or weekly basis.

1. I am creating reports using an Excel file as data source.  Can I create reports without creating a data model as in Tableau or Qlikview for example.  Currently I create a data model that just has this Excel file and it works fine for just one time import.
2. What if I need to refresh this data source on a periodic basis - daily, weekly etc.  Do I need to delete the existing file from the data model and then import and link the newly imported file with the same name?  If I do that, would the report connection to the data source need to be refreshed?
3. Can I edit the file in the model (created for the first time when I import the Excel file) to append newly added rows from another Excel file using a timestamp? 

Thank you
Nades341

#CognosAnalyticswithWatson

What version of Cognos Analytics are you using?

To answer your questions:

1. You do need to create a data module to use Report Authoring.  You can create a dashboard without doing so.
2. You do not need to delete the file, you can select the replace file option to refresh the data.  You can then just re-run the report.  You also have the option to link the data module to a new file, this is the relink option on the source panel in the Data Module source UI.

Replace: https://www.ibm.com/support/knowledgecenter/en/SSEP7J_11.1.0/com.ibm.swg.ba.cognos.ca_gtstd.doc/t_gtsd_upload_files_updates.html

Relink: https://www.ibm.com/support/knowledgecenter/en/SSEP7J_11.1.0/com.ibm.swg.ba.cognos.ca_mdlg.doc/t_ca_mdlg_relink_source.html

3. Cognos Analytics 11.1 does support the ability to append rows from another excel file.

Cheers,
Rob