This article describes how to use an alternative Excel interface to improve the performance of template instantiation.

Situation

When you use template instantiation you can use either a TestSheet or an ExcelSheet as your data source.
If an ExcelSheet is used, Tosca will communicate via a special interface with the locally installed MS Excel instance to retrieve data.
This approach works very well but can get very slow when the test instances defined in your excel sheet span over a larger number of rows and columns.

As a matter of fact the retrieval of data via this interface can sometimes take several minutes for large sheets which is caused by the technical nature of the interface offered by MS Excel.
 

Solution

If performance becomes an issue during template instantiation there is now an option to switch to a different kind of excel interface.
To switch the interface you need to open the options dialog within Tosca (Project -> Options) and check the option "Use alternative MSExcel interface".

https://tricentis.service-now.com/sys_attachment.do?sys_id=654a8384376ede40406642f643990e1b" style="height:544px; margin-bottom:0px; margin-left:0px; margin-right:0px; margin-top:0px; width:840px" />

This alternative excel interface has two major advantages:

• It doesn’t require an installed instance of MS Excel.
• It is much faster than the other interface.

But it also comes with two drawbacks:

• If your excel sheet contains HLOOKUP and VLOOKUP cells those values will not be supported.
  It is suggested that you copy/past your sheet and resolve those formulas so the cells just contain values.
• This new interface only works for excel files in the OpenXML format (*.xlsx)