Natalie,
Assuming you want to know the final yield, the method that I have used, is to set a new column to equal either a 1 or 0 based upon finding all passing, or finding at least one fail. The formula I use is to find the minimum of the boulian comparisons. For an example, if you have columns A, B, and C that have either a "Pass" or "Fail" value, I put the following formula into the new column called "Yield"
Min(:A=="Pass",:B=="Pass",:C=="Pass")
If all tests pass, the Min will be a 1, if not it will be a 0.
Then I simply do a Tables==>Summary and ask for %Total. and then delete the row for the "Fails" and then join with your summary table.
If you need the Yield for each parameter, then I would use an Analyze==>Tabulate, with the parameters down the rows, and the Pass and Fail as the columns. You can then Make into Data Table, and delete the "Fail" Column, and join this with your summary table.
Jim