Hi Yvette,

You can maintain a live connection to a PDF as a data source, but you will need to ensure that the PDF formatting and references do not cause problems when you replace the PDF file for a new one.  Much like any flat file connection, Tableau will expect that information in the data source have not changed and that field references will remain available in the new file.  What I might be mindful of is if the document shifts the location of the data table or modifies the structure of the table;  this is something can see happening in PDFs that may break reference and where it might be easier to standardize the data outside of the document if you plan to maintain reporting long term from that data source.  Other than that, you might take a look at Interwork's suggestion around updating a connection with new data: https://www.interworks.com/blog/mfowler/2013/07/08/editing-connections-tableau